Hey I got a question, if the battery is good at 12.6 and when the car first starts it's at 14v, but after say a half hour of stop and go traffic the voltage drops down anywhere from 11-13v at stop lights with the headlights on, but when speeding back up it slowly climbs above 13 and at highway speed will end up at 13.3 after a bit of driving, does that sound like it's failing? Wit hheadlights, defogger and wipers on the headlights dim and blower slows at stops, speeds up when driving.
One trick for cleaning battery terminals is using a baking soda/water past. It breaks down all the junk and neutralizes any acid left on them so they tend to corrode again.
Thanks for giving fun videos that are also so helpfull!!!
I have a question: Can an overchargeing alternator/regulator cause instrament lights to come on? All of a sudden one day my intrament cluster went crazy and lit everything(oil,brake,alt). My alternater charged to 15.49 once and 15.57once. Could that small amount of overcharge cause the lights to come on? (2001 mits. galant internal regulator)
Hey Eric I just replace the alternator on my corolla & sometimes I noticed that the battery & brake light flickers on & off randomly when I'm driving,I thought it could be the corrosion so I cleaned it but I'm still having the same problem..I also checked the voltage on my battery & it was alright,do you know what's causing the problem?? Or could it be the wiring??
I just replaced the alternator in a 94 tracker and it was failing to charge the battery. I didn't know what to do and I was getting a lot of bad and complicated advice. I came across this video, watched it, watched the one on belt & pulley basics, and was able to correctly diagnose the problem and fix it in about an hour (it was the belt). This is a remarkable series and I intend to let as many people know about it as possible. Be safe. Have fun. Stay dirty.
Try this to check for bad alternator: 1. Check ALT fuse is ok 2. Start car 3. Make sure alternator pulley is going around 4. Disconnect battery lead 5. If engine stops - fit new alternator. Easy.
I was having a problem with the Alternator, so I gave it a few whacks with a hammer and it started working again. I've been having to do this quite frequently for the past few weeks until I can replace it. What is happening for it to start working again after hitting it? There's been times where I had to pound on it to get it to start charging.
I wired my rad fan with 16 ga. wire. The fan quick-connect melted, and the relay heated up. I switched to 10 ga. wire and no problems. Why do 100/105 amp Delco CS130 D alts. only have an 8 ga. batt output wire? Ideally, the batt terminal on the alt. should have a 1 ga. output to the battery, with a similar amp. inline fuse. Delco recommends that battery be fully charged before car is started. The ASVR detects voltage and only turns-on when batt voltage drops a tad. Time for a smoke.
Eric, a comment / question about putting a big load on the battery to reduce what you called surface charge, I've not heard that term before. Specifically though, my question relates to running the starter with the ignition disabled. When emissions systems began using catalytic converters, I was told you shouldn't to any testing with the engine that would result in raw gas running through the exhaust, causing potential harm to the converter. Comment please?
right about the series part,but i meant pin pointing it actually. the method of pulling fuses isnt always the answer. i wish i had the examples in mind now ,but i dont ,sorry.
hey bud i just replaced my alt belt everything runs sweet but when i turn the lights on low and high beam or any stress on the alt it makes a bad sound not a squealing sound not the lose belt sound the sound of bad bearings like nails on a chalk board. would that be bad bearings and could i just give it a real good clean and a bit of lub on there would it fix it? or would i have to get a new alt. i can upload a video if it helps.
@lukesheridan1992 Honestly it's impossible for me to say but if the noise is coming from the alternator and the belt tension is correct then it probably needs to be replaced I don't think lube will help.
Sweet video, but I have two alternators. How do you suggest testing for charging issues with two alternators? Also how do you tell the diffrence between alternators and magnetos because I am not sure if I have alterntors or magnetos?
@10Secondcopper I would take the readings right at the output of the alternators themselves. You could also disconnect one at a time to see what they are putting out.
right eric its a parastic drain. but using the voltage drop test is the best way i know to deal w that thief. cant wait for the new videos. your work is appreciated.
@Placer Actually for a parasitic draw test you use an ammeter in series with the ground cable. I'll be putting a video out on this next month. Thanks for the comment.
Hello, quick question. I have a 98 Ford Taurus. Just recently, after I turn my car off the battery drains down, and a few hours later the battery dies. When I try to start the car it barely coughs to life, but after I start it up and drive the battery charges up, then drains down again after I turn it off. Any idea what this might be?
@rkodavey It sounds like you might have a parasitic draw meaning that something is still drawing power from the battery after you shut it off. To test for this you put an ammeter in series with the positive battery cable and look at the amp draw, it shouldn't be more than 50ma but a reading of less than 20ma is ideal. If you find you have a draw then pull the fuses one by one till you see the draw go away as that would indicate the effected circuit. I hope to make a video on this.
@urx44 I've known people that do that and it does work for the most part but on some cars you run the risk of damaging the electrical system doing it that way so be careful. Thanks for the comment.
@urx44 this is not a good thing to do, removing the positive cable can ruin the diodes in the regulator, this is bad, specially if the regulator is built in to the ECM, meaning you would have to replace the entire ECM. Best method is as shown in this video, get an inexpensive volt meter.
When i turn my truck off the temp and fuel Gauges turns back on then off then on again all day long Never stops. Could this be caused by a bad alternator?
I changed the alternator in my car. I have a 93 Honda Accord. At first it worked great and charged. After a while I noticed that my battery light would come on after driving for less than a mile, but if I stop and just held my brakes down, it would charge fine. What would that be? A loose belt?
@TheJasoncash83 check your belt first, these cars have a manual adjust tensioner, if its loose, the alternator will not put out enough voltage, the belt will not necessarily squeal when its loose
@MrAtaristic went ahead and changed both. I figured since the belt was loose, it preetty much burned by regulator out. Changed both and it's running like brand new
@nico27004 Toyota isn't that big on putting different electrical specs. It's very frustrating so i know how you feel. I was working on a 2000 Toyota Rav4.
My fathers suburban has been having some electrical issues all it's life really, recently it's also had a hard time starting in the morning when it's cold and damp. As far as I know that's fixed. I have always noticed at night you can see the lights flickering in a way, sort of like a rapid voltage drop that cycles at a constant rate, all I can think that would cause that is the alternator but they refuse to believe that, is there ANY thing else asides insulation that would do that?
@sunnymuffins13208 I should also add that I live in California so our climate is hot marginally humid and winters are wet and cold, it's a 99 and only really gets driven around town and makes the occasional 2-4 hour trip.
@sunnymuffins13208 If you have a security system that would be suspect but if you suspect an issue with the starter try some of the testing in this video to help you nail it down. The truth is it could be a lot of things but first you need to find the suspected circuit, I hope the info in the video will help. Good luck.
@sunnymuffins13208 I'm not sure the alternator would cause a condition like that. I had similar electrical issues on this vehicle that were caused by a leaking windshield where the water would run down the 'a' pillar and get into the fuse box.
Im so pissed of at my car man. The first long distance trip, it broke down and got my alternator replaced because it got burned. after the trip, everything went well but every 2 or 3 weeks, the battery dies and i have to get it charged. i finally bought a new batteries because my mitsubishi pajero needs two, and now, it wont even last 2 or 3 days. i took it to an electrician and they said they fixed the wires. so i have a new alternator, batteries, and good wires. what is wrong? please help man?
@510musicmaker Honestly I don't know but if you do the testing in this video it will go a long way to help you find the problem. New parts don't always equal a fix, take some time to see if you can figure out what's going on first. Good luck.
@nico27004 A factory manual would be a better choice but given that they are pretty close as I said before it sounds about right for a vehicle of that age.
@nico27004 I really can't say without knowing what vehicle and engine. Your best bet would be to consult the service manual for your vehicle for what the spec should be but they all look pretty close which is a good sign.
hey eric, wondering if you could tell me what the external fan does on a alternator is it just to cool it or does it do summat else thanks gr8 channel btw
ERIC my battery shows 12.2volts and i can just start my truck(barely) , i ran it with the hot off the battery and all was well so what is the problem, as im afraid to go anywhere now without keeping the engine running? HELP???
Hey Eric, I tried doing a voltage drop test from the positive battery terminal to the alternator b+, car on but no accessories. I then got a reading of 0.4 volts. There is obviously something I must have done wrong. Aren't I supposed to get a reading of at least 9.6 volts (12.6 at best)? If so is it because the accessories must absolutely be on for this positive output reading?
@ThaSavor I don't believe you are performing the test correctly I would recommend re-watching the video to see how to perform the test and for what the expected result should be as I'm not entirely sure what you are trying to diagnose.
@TheG10G11 If the engine isn't cranking you probably should look to that first and check the starter circuit, after you get the engine running you can then check the alternator.
well it charges so all is good....as for the lightbulb.......that cluster is a couple bulbs for illumination and a lot of garbage inside,and won`t tear it apart for 1 bulb
How odd is it that a week after I saw this video, I needed a new battery? Well, I did manage to get five years out of an original 3 year mopar battery.
ok so today my air conditioner stopped working, and like the lights and stuff still worked, than later that day when i turned the car back on the lights were on and i was driving and they just shot off and i put on my 4 ways, so is it a bad battery or....
ok took out lil light at ign switch......noticed NO battery light when turned on......bulb burned out?.....got the new alt. on and still no battery light when key is on.
@jeepers2655 It should only come on for a moment for the 'bulb check' when you first start the car but if it's not coming on and you know that the alternator is charging then it very well could be a bad bulb in the cluster.
Hey Eric, I just put the meter to the battery, turned on all for the power buttons and started the car like you said on the video. My meter was a reading 12.68V with everything on. Is that a bad alternator??
ok I let my charger ,charge the 90 honda accord battery.....well now it says 14.5 volts! not normal 12......so I turned everything on and never really wavered from the 14.5 to 14 but it did go to 13.79 or so .....oh yeah that stupid light on the ignition switch stays on also......I know that`s a drain too......how to disable that?? it used to fade out,now its on all the time!..........thanks.
@jeepers2655 The idiot light circuit is housed inside the alternator regulator assembly, there may be a problem with it or the wiring going to the dash.
Hey Eric I need your help on a serious question. I just replaced an alternator on a subaru outback and the new alternator copper wires look to have a shiny glossy black color to them! They were not that way when i bought the alternator from Advance auto parts. It's only been two weeks since I installed it! The spiral copper wires inside the alternator are turning black. The old alternator had this too! Thats why i replaced it. What causes this??? Is it serious?
@MoneyMarcMes First make sure your voltages are correct as I demonstrate in this video, if they are I would say it's a normal condition as sometimes the sealants they use for those windings will change color after they are exposed to heat.
Thanks for replying to my question and I asked the same question to Advance Auto Parts and they said the same thing you did. They said the windings are sprayed with a protective coating and they said its burning off. That would explain the glossy black color! LOL!!! Learn something new everyday. Thanks for all you do! You the man!!!!
Hey Eric I love your show and i hope to be a mechanic one day. I really enjoy your videos and the accord timing belt video has also been helpful to me, but on to my question. My family has a 98 Pontiac sunfire with a pulsing problem with the lights, we think it's the alternator, but your opinion would be appreciated.
@bakyardbush762 I recommend doing the tests in this video to confirm your suspicions. Good luck with your new career choice, I have some videos on my other channel ETCG1 that might be helpful to you if you want to check those out.
@bakyardbush762 i had the exact same problem about 3 months ago. i took my car to the shop and they replaced the alternator. the timing worked out where this happened before i knew anything about Eric and his videos, and got a digital multimeter. i may have been able to save money by diagnosing the problem myself and definitely by replacing the alternator on my own. it's not hard. good luck!
@MoneyMarcMes Normally you won't because just about every modern system I've seen has it housed inside of the alternator assembly. External regulators are mostly on older cars and heavy equipment.
dam i had 2 watch this a few times 2 take it all in very nice vid thanks 4 posting! have u ever heaed that if take off a battery termial off your battery while its runing that it cam damage your electrcial system? oh yea if you store an extra battery on a cement floor is pice off wood under the battery to stop voltage leak?
@peckiledorf Some people have used that cable trick to determine if the alternator is good or not, on modern cars this is not a good idea because there is potential to damage some of the electrical components on the car. As for putting a battery on the floor it's more of an issue of putting the battery down on a small rock or something that can damage the case more than it is something that would cause a voltage leak.
i'm having an issue related to something electrical on my bike. I don't know if you know that much about em. But the battery died. I don't think it's cause of the alternator. But whenever i stop the bike after jumping it with a booster pack. The engine just cuts off when i come to a full stop. Does that mean that there is a short in the wiring that cause the battery to drain to?
@EpiDemic117 I have no idea, diagnosis involves a bit more than reading a general description. I will say however you don't want to overcomplicate your diagnosis, don't jump to the conclusion it's an electrical problem right off the bat instead look for common simple causes to problems, the rule of KISS, Keep It Simple Stupid.
@EricTheCarGuy yes i do understand the idea behind simplicity, i revolve around everyday. But this is not that simple. This bike was made in the 1980's. Most machines built in the 80's had big trouble with the electrical. There is this weird thing that connects straight to the battery, I don't know what it does. Searching for a diagram right now to find out. Hmm it might actually be that thing that drained the battery and causes the engine to be killed. i'll have to do it in stages.
When checking ground straps, on rear drive vehicles (north-south) the ground strap will generally go from battery to chassis to engine. On east-west layout, most cars ive seen go from the chassis to the transmission.
yo Eric you know how i check my alternator if its not charging... ill keep the car on then ill take off the positive side of the battery off and see if it keeps running if it runs its good if it dies when you take off the positive side off that means the alternator is not working. save alot of time Eric lol what you think??
@vinceperez158 That test does work on older vehicles but on some modern vehicles you can cause damage to electrical components doing it that way so be mindful doing that on newer cars. Thanks for the input.
As an aside, many alternators fail due to worn brushes, brushes can easily be changed, in some applications like bosch in mercedes/audi/vw the brushes come with the VR, and in many cars like fords you can change the brushes without removing the alternator, but remember to check your bearings and clean your armature. You may also want to check the coil and diodes but that is beyond the scope of some.
Other things to note, in some charging systems the alternator is reliant on the battery light in the dash, if the bulb is burned out the VR will not auto sense and the alternator will not charge. Working alternators will produce a magnetic field which will draw a metal object to the rear of the alt while operating. Another way to test for corroded cables is a load tester you can test the cables at the starter terminals as well as the B+ post on the alt if voltage drops then its cable /connection
@aeligos It could be the compressor or AC system is having issue or it could be that the idle circuit is not functioning properly, I might start by checking into the AC system.
Thank for the fast reply and I will check out the volt regulator my next question is where is that located ? I have a 93 civic si don't suppose you have a idea where it can be found ? As always thanks for the help your videos are easy to understand and easy to follow much help !
i did this testing and found my alt. is putting out 15.5 all the time . when i test the resistance it is around 10 or even 14 when i put the leid on the neg pole and the other on the alt housing . i have a alt wine in my stereo along with my sterieo sound cutting out at 2 and 3000 rpm. also my head lights dim when the car is at idle speed i will post a video for you to see what i mean . love the videos so much help!! well done
@stewgjeff I'm thinking there may be a problem with the regulator circuit as it also contains the radio suppression circuitry, the whine in the radio is a good clue for this.
@Kevmo7 I believe you have what is called a 'parasitic draw' which means there is some circuit that is draining the battery as it sits with the key off. I tackle this with an ammeter in series between the positive cable and terminal, I pull fuses till I see the amps drop significantly, once I've found the fuse I look to the things on that circuit to nail it down further. A future video to be sure.
Brilliant video, Eric. Isn't it sad that with integrated units, you have to replace the whole alternator if the voltage regulator is bad.
My parts store will bench test my alternator for free (full field?). Do you have faith in that technique? Do you recommend it as a double check?
Duane at realfixesrealfast recommends a carbon pile resistor/ammeter to objectively test output. Watching your video, it sounds like that more accurate kind of testing is not often necessary....
@spelunkerd Duane's method will work just fine and has for years. Full fielding works well also if you are able to do that and not a bad 'double check'. The truth is that there is more than one way to go about a diagnosis you just need to choose the best one for your application.
Hi eric,cool vids car guy!just wondering if you ever had any experience with cold starts on 94-96 nissan primera's,sr 20 de?mine doe'snt start early morn but starts fine when hot.could it be the aac valve or temp sender?if I put my hand over the air flow meter it acts as a choke and the car starts.thanks for the tech vids eric.
@macki30 I don't remember for sure but I think that engine uses a cold start injector, if that is the case I would check and verify the operation of that circuit if I was having a cold start problem.
@disnukka79 The best way to check injectors is with a fuel pressure gauge and some noid lights, I don't recommend removing them to check for a problem at first because you can gather evidence without having to remove them. If you watch the EGR video I did however I take a fuel rail off.
@DrJerryrigger I believe that would be a good topic for another video, the point of this one was to familiarize people with the prospect that other things can cause a charging problem and they should be checked before replacing an alternator, if a diode were bad I believe the alternator would not be able to perform correctly and would show up during this testing. Thanks very much for your comment.
@jazzy4me4eva Indeed they are. It's funny though they go through all the effort to show their appreciation and all I have to do is keep making videos. :)
My alternator puts out between 13.5 and 13.76V between idle and 5.000RPM and it doesn't drop more than 0.5V when I turn on the consumption. 13.7V is not much, but it doesn't go down very much, eather. What does this mean?
great videos, i really enjoy all of them...ive watched almost all of them and im a new subscriber...i was wondering if you could do a video on how to do a tire rotation yourself at home to save some people money for rotations
eric what if your car has regulator intergated into the pcm just wanting to know how you would fix that problem do you replace the pcm and have fashed at the dealer thanks.
@12344richard Good question. In a case like that I'm going to say check the service manual for the procedure on that, however I think many ECU's get a signal from the voltage regulator on the alternator, I haven't seen a regulator located inside an ECU but I also haven't seen everything so I really don't know if they are out there or not.
@moofushu Normal water has impurities that can cause a buildup inside the battery thus making it less efficient, it's best to use distilled when filling a battery.
great vid eric!nice job showing the voltage drop testing,a far superior method for testing for bad circuits than resistance testing.GOD bless you eric.
@EricTheCarGuy i have a 2002 Volkswagen i just purchased...it has over 100,000 miles...these transmissions apparently have "sealed" trannys...wondering if i should still take it to a mechanic to change and put fresh tranny fluid? my gut says to do it...please reply and thank you for puting out these vids
@d3v3ouzm1ndz Some shops have a great machine for doing that very thing. If I'm honest I'm not as familiar with VW's so I really couldn't speak specifically about your car.
Hi Eric, I've after market Grounding Cables connect to negative battery and all 5 lead cables connect to firewall, alternator, throttle body near the sensors and gearbox. All 5 lead wires are measure with my Digital DC Clamp meter to find where are more current draw are the best location. Please advice?
Hey I got a question, if the battery is good at 12.6 and when the car first starts it's at 14v, but after say a half hour of stop and go traffic the voltage drops down anywhere from 11-13v at stop lights with the headlights on, but when speeding back up it slowly climbs above 13 and at highway speed will end up at 13.3 after a bit of driving, does that sound like it's failing? Wit hheadlights, defogger and wipers on the headlights dim and blower slows at stops, speeds up when driving.
Subparanon 13 hours ago
One trick for cleaning battery terminals is using a baking soda/water past. It breaks down all the junk and neutralizes any acid left on them so they tend to corrode again.
mikezaq1 1 day ago
kick ass eric! volvo tech here, i just want to say that farmers arent the only ones outstanding in their feild!!! LOL
flankdrive45 4 days ago
top video,+10
iulixxx 6 days ago
dude, your head is crooked
gghouck 1 week ago
This has been flagged as spam show
Hey Erik,
Thanks for giving fun videos that are also so helpfull!!!
I have a question: Can an overchargeing alternator/regulator cause instrament lights to come on? All of a sudden one day my intrament cluster went crazy and lit everything(oil,brake,alt). My alternater charged to 15.49 once and 15.57once. Could that small amount of overcharge cause the lights to come on? (2001 mits. galant internal regulator)
rayraythejet 1 week ago
Comment removed
rayraythejet 1 week ago
Hey Eric I just replace the alternator on my corolla & sometimes I noticed that the battery & brake light flickers on & off randomly when I'm driving,I thought it could be the corrosion so I cleaned it but I'm still having the same problem..I also checked the voltage on my battery & it was alright,do you know what's causing the problem?? Or could it be the wiring??
Gshock714 1 week ago
I just replaced the alternator in a 94 tracker and it was failing to charge the battery. I didn't know what to do and I was getting a lot of bad and complicated advice. I came across this video, watched it, watched the one on belt & pulley basics, and was able to correctly diagnose the problem and fix it in about an hour (it was the belt). This is a remarkable series and I intend to let as many people know about it as possible. Be safe. Have fun. Stay dirty.
deebry62 1 week ago
ballpark figure.... what would it cost to replace alternator with labor? is it a time friendly task? thanks for the help
WlSEGUY 2 weeks ago
You favor George Clooney.
bootyman234 1 month ago
Try this to check for bad alternator: 1. Check ALT fuse is ok 2. Start car 3. Make sure alternator pulley is going around 4. Disconnect battery lead 5. If engine stops - fit new alternator. Easy.
elwood98034 1 month ago
This has been flagged as spam show
How do you replace alternator on Ford Escape XLT 3.0 V6 2001? DO YOU KNOW? THANK YOU!
MrSIR713 1 month ago
Comment removed
MrSIR713 1 month ago
I was having a problem with the Alternator, so I gave it a few whacks with a hammer and it started working again. I've been having to do this quite frequently for the past few weeks until I can replace it. What is happening for it to start working again after hitting it? There's been times where I had to pound on it to get it to start charging.
akjflynn 1 month ago
I wired my rad fan with 16 ga. wire. The fan quick-connect melted, and the relay heated up. I switched to 10 ga. wire and no problems. Why do 100/105 amp Delco CS130 D alts. only have an 8 ga. batt output wire? Ideally, the batt terminal on the alt. should have a 1 ga. output to the battery, with a similar amp. inline fuse. Delco recommends that battery be fully charged before car is started. The ASVR detects voltage and only turns-on when batt voltage drops a tad. Time for a smoke.
seapeddler 1 month ago
Eric, a comment / question about putting a big load on the battery to reduce what you called surface charge, I've not heard that term before. Specifically though, my question relates to running the starter with the ignition disabled. When emissions systems began using catalytic converters, I was told you shouldn't to any testing with the engine that would result in raw gas running through the exhaust, causing potential harm to the converter. Comment please?
donaldo1954 1 month ago
once again you know what your doing :P
MasterOfAllBass 2 months ago
right about the series part,but i meant pin pointing it actually. the method of pulling fuses isnt always the answer. i wish i had the examples in mind now ,but i dont ,sorry.
Placer 2 months ago
hey bud i just replaced my alt belt everything runs sweet but when i turn the lights on low and high beam or any stress on the alt it makes a bad sound not a squealing sound not the lose belt sound the sound of bad bearings like nails on a chalk board. would that be bad bearings and could i just give it a real good clean and a bit of lub on there would it fix it? or would i have to get a new alt. i can upload a video if it helps.
lukesheridan1992 2 months ago
@lukesheridan1992 Honestly it's impossible for me to say but if the noise is coming from the alternator and the belt tension is correct then it probably needs to be replaced I don't think lube will help.
EricTheCarGuy 2 months ago
Sweet video, but I have two alternators. How do you suggest testing for charging issues with two alternators? Also how do you tell the diffrence between alternators and magnetos because I am not sure if I have alterntors or magnetos?
10Secondcopper 2 months ago
@10Secondcopper I would take the readings right at the output of the alternators themselves. You could also disconnect one at a time to see what they are putting out.
EricTheCarGuy 2 months ago
Is the voltage reading on the battery true for all batteries/cars (i.e. 12.4V)?
doktor2007 2 months ago
@doktor2007 Yes, a fully charged 12v car battery should read at least 12.6v.
EricTheCarGuy 2 months ago
@EricTheCarGuy how do you magicly rev the engine up @ 4:24 and how can you tell how much rpm you are doing?
TheBeyBladeNation 1 month ago
Thank
You
Dethreid 2 months ago
* checking VD across fuses
Placer 2 months ago
right eric its a parastic drain. but using the voltage drop test is the best way i know to deal w that thief. cant wait for the new videos. your work is appreciated.
Placer 2 months ago
@Placer Actually for a parasitic draw test you use an ammeter in series with the ground cable. I'll be putting a video out on this next month. Thanks for the comment.
EricTheCarGuy 2 months ago
walmart charged my battery three months ago and suddenly there's nothing.
no start, no noise, neither the lights or the locks work.
chr0nicForc3 2 months ago
@chr0nicForc3 You might check the battery connections.
EricTheCarGuy 2 months ago
Hello, quick question. I have a 98 Ford Taurus. Just recently, after I turn my car off the battery drains down, and a few hours later the battery dies. When I try to start the car it barely coughs to life, but after I start it up and drive the battery charges up, then drains down again after I turn it off. Any idea what this might be?
rkodavey 3 months ago
@rkodavey It sounds like you might have a parasitic draw meaning that something is still drawing power from the battery after you shut it off. To test for this you put an ammeter in series with the positive battery cable and look at the amp draw, it shouldn't be more than 50ma but a reading of less than 20ma is ideal. If you find you have a draw then pull the fuses one by one till you see the draw go away as that would indicate the effected circuit. I hope to make a video on this.
EricTheCarGuy 2 months ago
Is that a 4.3 Vortec V6? i love those engines...
XHikotheproX 3 months ago
@XHikotheproX I think so yes.
EricTheCarGuy 2 months ago
one good method i always use is take da + cable of the battery while running and it it shuts off its your alternator plain and simple
urx44 3 months ago
@urx44 I've known people that do that and it does work for the most part but on some cars you run the risk of damaging the electrical system doing it that way so be careful. Thanks for the comment.
EricTheCarGuy 2 months ago
@urx44 this is not a good thing to do, removing the positive cable can ruin the diodes in the regulator, this is bad, specially if the regulator is built in to the ECM, meaning you would have to replace the entire ECM. Best method is as shown in this video, get an inexpensive volt meter.
MrAtaristic 2 months ago
for those wondering about losing power when the car is off and supposedly all accs are off ,try a voltage drop test. its going somewhere
Placer 3 months ago
@Placer For that a parasitic draw test would apply I believe, I hope to make a video on that soon. Thanks for the comment.
EricTheCarGuy 2 months ago
When i turn my truck off the temp and fuel Gauges turns back on then off then on again all day long Never stops. Could this be caused by a bad alternator?
My02S10 3 months ago
@My02S10 Probably not but if you suspect an alternator problem you could perform the tests in this video to find out.
EricTheCarGuy 3 months ago
Wow Ty for your video help a lot
wolffreewolf 3 months ago
@wolffreewolf Glad you liked it, thanks for the comment.
EricTheCarGuy 3 months ago
@EricTheCarGuy your welcome
wolffreewolf 3 months ago
I changed the alternator in my car. I have a 93 Honda Accord. At first it worked great and charged. After a while I noticed that my battery light would come on after driving for less than a mile, but if I stop and just held my brakes down, it would charge fine. What would that be? A loose belt?
TheJasoncash83 3 months ago
@TheJasoncash83 Hard to say really, if you perform the tests in this video it should help you nail down the cause.
EricTheCarGuy 3 months ago
@TheJasoncash83 check your belt first, these cars have a manual adjust tensioner, if its loose, the alternator will not put out enough voltage, the belt will not necessarily squeal when its loose
MrAtaristic 2 months ago
@MrAtaristic went ahead and changed both. I figured since the belt was loose, it preetty much burned by regulator out. Changed both and it's running like brand new
TheJasoncash83 2 months ago
Great video. Thanks for taking the time to do this!
jataga1212 3 months ago
@jataga1212 Glad you liked it, thanks for the comment.
EricTheCarGuy 3 months ago
@nico27004 Toyota isn't that big on putting different electrical specs. It's very frustrating so i know how you feel. I was working on a 2000 Toyota Rav4.
reggielovesgirls 4 months ago
My fathers suburban has been having some electrical issues all it's life really, recently it's also had a hard time starting in the morning when it's cold and damp. As far as I know that's fixed. I have always noticed at night you can see the lights flickering in a way, sort of like a rapid voltage drop that cycles at a constant rate, all I can think that would cause that is the alternator but they refuse to believe that, is there ANY thing else asides insulation that would do that?
sunnymuffins13208 4 months ago
@sunnymuffins13208 I should also add that I live in California so our climate is hot marginally humid and winters are wet and cold, it's a 99 and only really gets driven around town and makes the occasional 2-4 hour trip.
sunnymuffins13208 4 months ago
@sunnymuffins13208 If you have a security system that would be suspect but if you suspect an issue with the starter try some of the testing in this video to help you nail it down. The truth is it could be a lot of things but first you need to find the suspected circuit, I hope the info in the video will help. Good luck.
EricTheCarGuy 4 months ago
@sunnymuffins13208 I'm not sure the alternator would cause a condition like that. I had similar electrical issues on this vehicle that were caused by a leaking windshield where the water would run down the 'a' pillar and get into the fuse box.
EricTheCarGuy 3 months ago
Im so pissed of at my car man. The first long distance trip, it broke down and got my alternator replaced because it got burned. after the trip, everything went well but every 2 or 3 weeks, the battery dies and i have to get it charged. i finally bought a new batteries because my mitsubishi pajero needs two, and now, it wont even last 2 or 3 days. i took it to an electrician and they said they fixed the wires. so i have a new alternator, batteries, and good wires. what is wrong? please help man?
510musicmaker 4 months ago
@510musicmaker Honestly I don't know but if you do the testing in this video it will go a long way to help you find the problem. New parts don't always equal a fix, take some time to see if you can figure out what's going on first. Good luck.
EricTheCarGuy 4 months ago
@510musicmaker Is it possible that power is somehow bleeding while the car is off even if nothing is turned on?
TehBerbDean 3 months ago
its a 1984 toyota pickup 22re engine. i cant find what the specs would be. i have a haynes manual
nico27004 4 months ago
@nico27004 A factory manual would be a better choice but given that they are pretty close as I said before it sounds about right for a vehicle of that age.
EricTheCarGuy 4 months ago
i did a compression test today on my car and i got 130,125,125,120. is that normal?
nico27004 4 months ago
@nico27004 I really can't say without knowing what vehicle and engine. Your best bet would be to consult the service manual for your vehicle for what the spec should be but they all look pretty close which is a good sign.
EricTheCarGuy 4 months ago
can anyone tell me why my car stereo turns on and off ..when the car is running .. but i has a new stereo...
cHEpZ07 4 months ago
@cHEpZ07 I would say start by checking over the installation to make sure everything is connected properly.
EricTheCarGuy 4 months ago
hey eric, wondering if you could tell me what the external fan does on a alternator is it just to cool it or does it do summat else thanks gr8 channel btw
wicked2631 4 months ago
@wicked2631 The alternator can get very hot doing it's work so it needs the fan to help keep it cool.
EricTheCarGuy 4 months ago
HAHA is that a burban? if so i got the same Burban GMC 1999 i just replaced the alt today!
bw110719 4 months ago
@bw110719 It is the same as the one you have a 99.
EricTheCarGuy 4 months ago
ERIC my battery shows 12.2volts and i can just start my truck(barely) , i ran it with the hot off the battery and all was well so what is the problem, as im afraid to go anywhere now without keeping the engine running? HELP???
ricglos 5 months ago
@ricglos Static battery charge should be 12.6 or above at 70º, I would suggest testing the battery first.
EricTheCarGuy 4 months ago
Hey Eric, I tried doing a voltage drop test from the positive battery terminal to the alternator b+, car on but no accessories. I then got a reading of 0.4 volts. There is obviously something I must have done wrong. Aren't I supposed to get a reading of at least 9.6 volts (12.6 at best)? If so is it because the accessories must absolutely be on for this positive output reading?
ThaSavor 5 months ago
@ThaSavor I don't believe you are performing the test correctly I would recommend re-watching the video to see how to perform the test and for what the expected result should be as I'm not entirely sure what you are trying to diagnose.
EricTheCarGuy 5 months ago
How to test a alternator when engine wont crank? How to "benchtesting" it?
As always good movies Eric, it's reliable and calm and a bit funny!
TheG10G11 5 months ago
@TheG10G11 If the engine isn't cranking you probably should look to that first and check the starter circuit, after you get the engine running you can then check the alternator.
EricTheCarGuy 5 months ago
to test alternator where were the leads connected? I presume to the battery terminals judging by what I can see in the viddy
hambone5126 6 months ago
@hambone5126 Depends on the test, you might want to watch the video again as I took great pains to show how the tests were performed.
EricTheCarGuy 5 months ago
It goes up to 13.8 fully loaded
SuperchargedMustang5 6 months ago
@SuperchargedMustang5 Sounds fine to me.
EricTheCarGuy 6 months ago
My voltage is 13.4 at idle and everything off
SuperchargedMustang5 6 months ago
@SuperchargedMustang5 That sounds good but you should check it loaded if you are trying to see what it's capable of.
EricTheCarGuy 6 months ago
well it charges so all is good....as for the lightbulb.......that cluster is a couple bulbs for illumination and a lot of garbage inside,and won`t tear it apart for 1 bulb
jeepers2655 6 months ago
@jeepers2655 Like you said if it's charging all is good, I think I would let the bulb go too.
EricTheCarGuy 6 months ago
How odd is it that a week after I saw this video, I needed a new battery? Well, I did manage to get five years out of an original 3 year mopar battery.
EricWaterTruck 7 months ago
@EricWaterTruck I'm happy to be around when you need me. :) You must have jedi powers when it comes to batteries.
EricTheCarGuy 7 months ago
thank you eric , superb info , awesome , enough said
radattt 7 months ago
@radattt Glad you liked it, thanks for the comment.
EricTheCarGuy 7 months ago
ok so today my air conditioner stopped working, and like the lights and stuff still worked, than later that day when i turned the car back on the lights were on and i was driving and they just shot off and i put on my 4 ways, so is it a bad battery or....
voteforitnow 7 months ago
@voteforitnow Don't know, I would start by checking the battery and it's connections however.
EricTheCarGuy 7 months ago
ok took out lil light at ign switch......noticed NO battery light when turned on......bulb burned out?.....got the new alt. on and still no battery light when key is on.
jeepers2655 7 months ago
@jeepers2655 It should only come on for a moment for the 'bulb check' when you first start the car but if it's not coming on and you know that the alternator is charging then it very well could be a bad bulb in the cluster.
EricTheCarGuy 7 months ago
Hey Eric, I just put the meter to the battery, turned on all for the power buttons and started the car like you said on the video. My meter was a reading 12.68V with everything on. Is that a bad alternator??
realjdmek9 7 months ago
@realjdmek9 Actually I would say that is a good reading and the alternator is working fine.
EricTheCarGuy 7 months ago
ok I let my charger ,charge the 90 honda accord battery.....well now it says 14.5 volts! not normal 12......so I turned everything on and never really wavered from the 14.5 to 14 but it did go to 13.79 or so .....oh yeah that stupid light on the ignition switch stays on also......I know that`s a drain too......how to disable that?? it used to fade out,now its on all the time!..........thanks.
jeepers2655 7 months ago
@jeepers2655 The idiot light circuit is housed inside the alternator regulator assembly, there may be a problem with it or the wiring going to the dash.
EricTheCarGuy 7 months ago
Hey Eric I need your help on a serious question. I just replaced an alternator on a subaru outback and the new alternator copper wires look to have a shiny glossy black color to them! They were not that way when i bought the alternator from Advance auto parts. It's only been two weeks since I installed it! The spiral copper wires inside the alternator are turning black. The old alternator had this too! Thats why i replaced it. What causes this??? Is it serious?
Thanks, Marc
MoneyMarcMes 7 months ago
@MoneyMarcMes First make sure your voltages are correct as I demonstrate in this video, if they are I would say it's a normal condition as sometimes the sealants they use for those windings will change color after they are exposed to heat.
EricTheCarGuy 7 months ago
@EricTheCarGuy Hi eric,
Thanks for replying to my question and I asked the same question to Advance Auto Parts and they said the same thing you did. They said the windings are sprayed with a protective coating and they said its burning off. That would explain the glossy black color! LOL!!! Learn something new everyday. Thanks for all you do! You the man!!!!
Marc
MoneyMarcMes 7 months ago
how many miles does an alternator usually go bad? Thanks
extremebiker2005 7 months ago
@extremebiker2005 No set mileage that I can think of really as there could be more than one cause for failure.
EricTheCarGuy 7 months ago
Hey Eric I love your show and i hope to be a mechanic one day. I really enjoy your videos and the accord timing belt video has also been helpful to me, but on to my question. My family has a 98 Pontiac sunfire with a pulsing problem with the lights, we think it's the alternator, but your opinion would be appreciated.
Thanks!
bakyardbush762 7 months ago
@bakyardbush762 I recommend doing the tests in this video to confirm your suspicions. Good luck with your new career choice, I have some videos on my other channel ETCG1 that might be helpful to you if you want to check those out.
EricTheCarGuy 7 months ago
@bakyardbush762 i had the exact same problem about 3 months ago. i took my car to the shop and they replaced the alternator. the timing worked out where this happened before i knew anything about Eric and his videos, and got a digital multimeter. i may have been able to save money by diagnosing the problem myself and definitely by replacing the alternator on my own. it's not hard. good luck!
idan4411 7 months ago
How do you find the voltage regulator? How does that part look like?
Marc
MoneyMarcMes 7 months ago
@MoneyMarcMes Normally you won't because just about every modern system I've seen has it housed inside of the alternator assembly. External regulators are mostly on older cars and heavy equipment.
EricTheCarGuy 7 months ago
dam i had 2 watch this a few times 2 take it all in very nice vid thanks 4 posting! have u ever heaed that if take off a battery termial off your battery while its runing that it cam damage your electrcial system? oh yea if you store an extra battery on a cement floor is pice off wood under the battery to stop voltage leak?
peckiledorf 7 months ago
@peckiledorf Some people have used that cable trick to determine if the alternator is good or not, on modern cars this is not a good idea because there is potential to damage some of the electrical components on the car. As for putting a battery on the floor it's more of an issue of putting the battery down on a small rock or something that can damage the case more than it is something that would cause a voltage leak.
EricTheCarGuy 7 months ago
i'm having an issue related to something electrical on my bike. I don't know if you know that much about em. But the battery died. I don't think it's cause of the alternator. But whenever i stop the bike after jumping it with a booster pack. The engine just cuts off when i come to a full stop. Does that mean that there is a short in the wiring that cause the battery to drain to?
EpiDemic117 7 months ago
@EpiDemic117 I have no idea, diagnosis involves a bit more than reading a general description. I will say however you don't want to overcomplicate your diagnosis, don't jump to the conclusion it's an electrical problem right off the bat instead look for common simple causes to problems, the rule of KISS, Keep It Simple Stupid.
EricTheCarGuy 7 months ago
@EricTheCarGuy yes i do understand the idea behind simplicity, i revolve around everyday. But this is not that simple. This bike was made in the 1980's. Most machines built in the 80's had big trouble with the electrical. There is this weird thing that connects straight to the battery, I don't know what it does. Searching for a diagram right now to find out. Hmm it might actually be that thing that drained the battery and causes the engine to be killed. i'll have to do it in stages.
EpiDemic117 7 months ago
@EricTheCarGuy by linking that towards google search to see if it is linked as a common problem. Simplified!
EpiDemic117 7 months ago
When checking ground straps, on rear drive vehicles (north-south) the ground strap will generally go from battery to chassis to engine. On east-west layout, most cars ive seen go from the chassis to the transmission.
privatealpha 7 months ago
yo Eric you know how i check my alternator if its not charging... ill keep the car on then ill take off the positive side of the battery off and see if it keeps running if it runs its good if it dies when you take off the positive side off that means the alternator is not working. save alot of time Eric lol what you think??
vinceperez158 7 months ago
@vinceperez158 That test does work on older vehicles but on some modern vehicles you can cause damage to electrical components doing it that way so be mindful doing that on newer cars. Thanks for the input.
EricTheCarGuy 7 months ago
As an aside, many alternators fail due to worn brushes, brushes can easily be changed, in some applications like bosch in mercedes/audi/vw the brushes come with the VR, and in many cars like fords you can change the brushes without removing the alternator, but remember to check your bearings and clean your armature. You may also want to check the coil and diodes but that is beyond the scope of some.
PUREAAMERICAN 7 months ago
Other things to note, in some charging systems the alternator is reliant on the battery light in the dash, if the bulb is burned out the VR will not auto sense and the alternator will not charge. Working alternators will produce a magnetic field which will draw a metal object to the rear of the alt while operating. Another way to test for corroded cables is a load tester you can test the cables at the starter terminals as well as the B+ post on the alt if voltage drops then its cable /connection
PUREAAMERICAN 7 months ago
@PUREAAMERICAN Great info, thanks for the input.
EricTheCarGuy 7 months ago
@aeligos It could be the compressor or AC system is having issue or it could be that the idle circuit is not functioning properly, I might start by checking into the AC system.
EricTheCarGuy 7 months ago
you look really tired in this video
380gb 7 months ago
what kind of performance issues other than the battery not recharging would I notice?
wmp89 7 months ago
@wmp89 Depends on the depth of the problem but anything electrical may not function as it should.
EricTheCarGuy 7 months ago
Thank for the fast reply and I will check out the volt regulator my next question is where is that located ? I have a 93 civic si don't suppose you have a idea where it can be found ? As always thanks for the help your videos are easy to understand and easy to follow much help !
stewgjeff 7 months ago
@stewgjeff The voltage regulator on that vehicle is inside the alternator itself.
EricTheCarGuy 7 months ago
i did this testing and found my alt. is putting out 15.5 all the time . when i test the resistance it is around 10 or even 14 when i put the leid on the neg pole and the other on the alt housing . i have a alt wine in my stereo along with my sterieo sound cutting out at 2 and 3000 rpm. also my head lights dim when the car is at idle speed i will post a video for you to see what i mean . love the videos so much help!! well done
stewgjeff 7 months ago
@stewgjeff I'm thinking there may be a problem with the regulator circuit as it also contains the radio suppression circuitry, the whine in the radio is a good clue for this.
EricTheCarGuy 7 months ago
@Kevmo7 I believe you have what is called a 'parasitic draw' which means there is some circuit that is draining the battery as it sits with the key off. I tackle this with an ammeter in series between the positive cable and terminal, I pull fuses till I see the amps drop significantly, once I've found the fuse I look to the things on that circuit to nail it down further. A future video to be sure.
EricTheCarGuy 7 months ago
Brilliant video, Eric. Isn't it sad that with integrated units, you have to replace the whole alternator if the voltage regulator is bad.
My parts store will bench test my alternator for free (full field?). Do you have faith in that technique? Do you recommend it as a double check?
Duane at realfixesrealfast recommends a carbon pile resistor/ammeter to objectively test output. Watching your video, it sounds like that more accurate kind of testing is not often necessary....
spelunkerd 7 months ago
@spelunkerd Duane's method will work just fine and has for years. Full fielding works well also if you are able to do that and not a bad 'double check'. The truth is that there is more than one way to go about a diagnosis you just need to choose the best one for your application.
EricTheCarGuy 7 months ago
Hi eric,cool vids car guy!just wondering if you ever had any experience with cold starts on 94-96 nissan primera's,sr 20 de?mine doe'snt start early morn but starts fine when hot.could it be the aac valve or temp sender?if I put my hand over the air flow meter it acts as a choke and the car starts.thanks for the tech vids eric.
macki30 7 months ago
@macki30 I don't remember for sure but I think that engine uses a cold start injector, if that is the case I would check and verify the operation of that circuit if I was having a cold start problem.
EricTheCarGuy 7 months ago
Thank you for the informative video!
aikido8888 7 months ago
ERIC can you do a video about taking a fuel rail off... I need to check my injectors and 2 years ago had to have my fuel pressor regulator off.
disnukka79 7 months ago
@disnukka79 The best way to check injectors is with a fuel pressure gauge and some noid lights, I don't recommend removing them to check for a problem at first because you can gather evidence without having to remove them. If you watch the EGR video I did however I take a fuel rail off.
EricTheCarGuy 7 months ago
Great vid! The only thing missing is a diode test, though that's not possible with many newer alternators.
DrJerryrigger 7 months ago
@DrJerryrigger I believe that would be a good topic for another video, the point of this one was to familiarize people with the prospect that other things can cause a charging problem and they should be checked before replacing an alternator, if a diode were bad I believe the alternator would not be able to perform correctly and would show up during this testing. Thanks very much for your comment.
EricTheCarGuy 7 months ago
great job @ErickTheCarGuy this video was super helpful to me. thank brother
flowfresco 7 months ago
@flowfresco Your most welcome, thanks for the comment.
EricTheCarGuy 7 months ago
Good video! thanks Eric!
jonnielahti 7 months ago
great vid, as always, very informative
TheAstro30 7 months ago
Great video, Eric. Very thorough information here.
mazzmari 7 months ago
why are there always at least 4 dislikes on all your vids ... them people are haters
jazzy4me4eva 7 months ago
@jazzy4me4eva Indeed they are. It's funny though they go through all the effort to show their appreciation and all I have to do is keep making videos. :)
EricTheCarGuy 7 months ago
My alternator puts out between 13.5 and 13.76V between idle and 5.000RPM and it doesn't drop more than 0.5V when I turn on the consumption. 13.7V is not much, but it doesn't go down very much, eather. What does this mean?
cipmars 7 months ago
@cipmars Nothing really, it sounds healthy to me.
EricTheCarGuy 7 months ago
@EricTheCarGuy Thanks, Eric.
cipmars 7 months ago
I favorited this vid!!! :)
Electrical diagnosis is uber important for vehicles/motorcycles alike.
peelout40 7 months ago
@peelout40 Indeed, thanks for the comment.
EricTheCarGuy 7 months ago
great videos, i really enjoy all of them...ive watched almost all of them and im a new subscriber...i was wondering if you could do a video on how to do a tire rotation yourself at home to save some people money for rotations
Mikevanhagar 7 months ago
@Mikevanhagar That would be a great video, thanks for the suggestion, if I get the time I'd be happy to make that one for you.
EricTheCarGuy 7 months ago
eric what if your car has regulator intergated into the pcm just wanting to know how you would fix that problem do you replace the pcm and have fashed at the dealer thanks.
12344richard 7 months ago
@12344richard Good question. In a case like that I'm going to say check the service manual for the procedure on that, however I think many ECU's get a signal from the voltage regulator on the alternator, I haven't seen a regulator located inside an ECU but I also haven't seen everything so I really don't know if they are out there or not.
EricTheCarGuy 7 months ago
Hey Eric, love the electrical series videos. Hope you keep them coming. I watch every single one of your videos.
jbernhoft 7 months ago
@jbernhoft I like doing these too. I hope to go back and cover some more of the basics though.
EricTheCarGuy 7 months ago
Is it true only distilled water should only be added to lead acid batteries? If so, what can happen if you add normal tap water to a battery?
moofushu 7 months ago
@moofushu Normal water has impurities that can cause a buildup inside the battery thus making it less efficient, it's best to use distilled when filling a battery.
EricTheCarGuy 7 months ago
One of your best videos yet!
brakedd 7 months ago
@brakedd I liked it too. Thanks for the comment.
EricTheCarGuy 7 months ago
great vid eric!nice job showing the voltage drop testing,a far superior method for testing for bad circuits than resistance testing.GOD bless you eric.
kneedown4GOD 7 months ago
@kneedown4GOD I agree, thanks for the comment.
EricTheCarGuy 7 months ago
people all say check with the service manual but mine dosent tell me shit
Dillonj177 7 months ago
@Dillonj177 Service manual or owners manual?
EricTheCarGuy 7 months ago
Did anyone tell you yet that you are the "Mike Rowe" of Auto Repair?
jdouglasfisher 7 months ago
@jdouglasfisher High complements indeed, I love Mike Rowe. (no homo) :)
EricTheCarGuy 7 months ago
@EricTheCarGuy i have a 2002 Volkswagen i just purchased...it has over 100,000 miles...these transmissions apparently have "sealed" trannys...wondering if i should still take it to a mechanic to change and put fresh tranny fluid? my gut says to do it...please reply and thank you for puting out these vids
d3v3ouzm1ndz 7 months ago
@d3v3ouzm1ndz Some shops have a great machine for doing that very thing. If I'm honest I'm not as familiar with VW's so I really couldn't speak specifically about your car.
EricTheCarGuy 7 months ago
u did not turn on the flux capacitor.
DudeRanger1 7 months ago
@DudeRanger1 Of course, the shop is powered by Mr. Fusion.
EricTheCarGuy 7 months ago
Hi Eric, I've after market Grounding Cables connect to negative battery and all 5 lead cables connect to firewall, alternator, throttle body near the sensors and gearbox. All 5 lead wires are measure with my Digital DC Clamp meter to find where are more current draw are the best location. Please advice?
axenz1 7 months ago