How To Check Out The Alternator On Your Car

[cb7pwn]

funny, all your cars that have problems are American made .. **cough!**

[PleaseBuyMyCat]

@cb7pwn Some people donate their faulty cars so he can show us how to fix them. He's not going to take a car all the way from Japan...

[cabach34]

germans cars and japs cars #1

[SourDiesel400]

Scotty, I've noticed lately that my headlights are kind of dim (new bulbs), and my interior/dash lights are not as bright as they used to be. Also, the digital clock face fades in and out, but the rest of the CD player face remains lit. Could this be an alternator issue, or am I looking in the wrong direction? The vehicle is a '99 Dakota RT.

[scottykilmer]

@SourDiesel400 yep, have the alt and battery checked, places like auto zone do it free in their parking lots. Scotty

[armystrong8989]

scotty,...once upon i time i owned a blazer that kept blowing fuses when i put em in, never could find a short anywhere and did all sorts of crazy things to starting up by itself! i wish you were my next door neighbor

[laferriere78]

Shit Scotty, WTF! How To Check Out The Alternator On Your Car ??? Bulshit!!! You tell everybody to go get it checked, Not how to check. Change the Fkn title asshowl

[flyingmantis]

Scotty, when my engine is at idle, the battery is only measuring at 12.5 volt, however, as soon as I bring the rpm to 2000, the voltage would go up 13.6. Does this mean my alternator is not healthy and need replacing? Thanks!

[scottykilmer]

@Marshmallowrex yes, that can happen, Scotty

[scottykilmer]

@Marshmallowrex Many electrical problems can cause stuff like that, so start by having the alternator checked, places like auto zone do it free in their parking lots. Scotty

[FoxyWolfProductionz]

After seeing this i have added yet another possibility to my dilema. My horn works fine when stopped but when moving it will be hit and miss. Could this be the Alternator? I was thinking Dirty Contacts on the circuit or faulty Horn Relay. The Car is a 1994 Oldsmobile Cutlass Ciera S (just in case the info helps anything).

Thanks Scotty. More questions to come.

[scottykilmer]

@FoxyWolfProductionz dirty contacts on the steering wheel are more common. Scotty

[Sorman26]

Hello Scotty, the alternator on a 1990 Honda Civic CRX that I was working on had seized. Any ideas as to why? Plus, the second bolt, which is on the lower end is so rusted that it's difficult to remove the alternator back and forth. Any idea(s) to help remove that bolt as well? Thanks in advance.

[scottykilmer]

@Sorman26 bearings lock up, get a new alternator. Spray the nut on the bolt with WD 40 and hope that loosens it up overnight. Scotty

[yoshiD15]

@scottykilmer is my battery or my alternator after i turn on my car i unhook the battery and the whole car turns off? Acura integra 95

[scottykilmer]

@yoshiD15 bad alternator, but shoot the guy who told you to remove the battery cable with the car running. NEVER do that on a modern car, it can ruin the computer. Scotty

[NorkiddExo]

@scottykilmer I have an old 1966 chrysler sedan thats been sitting for about thirty years. I don't trust the alternator not to kill my 4x4 battery. If I started it and disconnected would it kill the alternator? I've always been told it would.

Plus the alternators been disconnected, could you tell me what lead goes from the alternator to the car and where you typically connect it (being the positive), (Engine ground negative).

[scottykilmer]

@NorkiddExo Not a good idea to run a car with the battery unhooked, even on those old things, it can short the diodes out on the alternator. As for the wires, can't remember on those old things, get a wiring diagram for that from a cheap old manual, my data base doesn't cover anything that old, it starts at 1982. Scotty

[abunaiN1]

haha i like this guy !!

[Tiggerpilot]

SCOTTY---LOVE YOUR ADVICE ON STUFF. I JUST APPLY A VOLT METER TO THE BATTERY WHEN IDLING....THE JUICE SHOULD READ ABOUT 14.0 VOLTS TO 14.6 VOLTS. 'COURSE....A BATTERY WITH A BAD/SHORTED CELL COULD DRAG IT DOWN. BOUGHT A SPARE ALTERNATOR FOR MY '92 FESTIVA...JUST IN CASE...AND FOR PROJECTS...NEVER NEEDED IT. GOT OVER 285,000 MILES ON THE CAR.NO MAJOR WORK NEEDED....& I HAVE BEAT THE SHIT OUT OF IT ON OCCASION...GETTING LOST IN VIRGINIA. THIS CAR WAS MADE IN KOREA FOR FORD MOTOR CO.

[rocknrolldaddio]

Whoa,my alternator is bad.Beam me up Scotty !

[tenchidbz]

Oh, so your in Michigan?

[scottykilmer]

@tenchidbz No, I'm in Texas, those are loaner trial Ford cars. Scotty

[jonathan99786]

I new it!!!!

[vitali1985]

contnd... so plz tell me if the head lamps problem is related to the alternator. the battariey is new (only few month old.) car is oldsmobile intrigue 1998. thanks in advance.

[scottykilmer]

@vitali1985 It certainly can be, low charging voltage can make headlights go bonkers. Scotty

[scottykilmer]

@vitali1985 if an alternator is not charging correctly, the headlights can be dim. But they can also be dim from bad ground wires. Scotty

[vitali1985]

@scottykilmer

thank you for the info! i guess the alternataor was bad, becouse i after i replased it everything went back to normal.

[vitali1985]

hi scotty i have a question. a few days after struglin in the snow storm for two and a half hours i started my car and niticed a battariy icon "on" [' + - ' ] i read the manual it says charging problem. and i guess the alternator had to be replaced. well it wasnt at its top condition anyway so that is not very big beal for me to take care of. but the problem is that my head lamps, on low and high beam, wont go on now only if i pull the lever back to bling his it goes on. fuses r ok it seams.

[slipcheck5]

You forgot to mention a fast way to check the alt. to see its bad is to leave the engine running and disconect the batterywire if the car engine dies then you know the alt is bad. Just thought i would mention that..☻

[spelunkerd]

@slipcheck5 I don't think I would risk doing that (disconnecting battery while running) in a modern car. The electronics of new vehicles is sensitive enough to voltage surges that you might damage something downstream....

[EvenSteven2004]

Hi Scotty, Great videos...but a quick question: Is it possible for me to check my alternator using a digital volt/ohm meter? Will I be able to see A/C ripple?

[underpantswedgy]

lol ur funny! 

[aliisathug]

how u fix a honda hatchback 92-95 with after market stering weel

[scottykilmer]

@aliisathug I have no idea what you want fixed? If you are having steering wheel problems, go to a junk yard and put an OEM wheel back on. Scotty

[zztopgearhead1]

scotty i noticed on my cavalier while driving at night the higher the engine rpms the dimmer my lights get but when the rpms are lower they are bright. what caused this

[scottykilmer]

@zztopgearhead1 Either the alternator can't handle the load and needs replacing, or the wiring is bad. I'd bet on the alternator. Scotty

[Tenkaichibudokai22]

How about bimmers (BMW´s) ? do they have the same problems? are they a good investment in general? Thanks in advance.

[scottykilmer]

@Tenkaichibudokai22 Beemers are only good investments for mechanics who have customers that drive them. They are endless money pit machines as they age. Scotty

[Tenkaichibudokai22]

@scottykilmer Alright Scotty! i'll listen to your words. Thanks!

[Berialavrenti]

mAY THE GODS OF THE ALTERNATOR BE WITH YOU, SCOTYY!

[youdragon]

if i put a 150 amp in place of my 105 amp alt will it kill my battery by over chargeing??? and if so hwo can i fix that? im putting about 520watts of off road lights onto my truck and need a alt that can handle it but those light wont always be on and i dont whant to damage my battery, any tips?

[scottykilmer]

@youdragon Get a very large amerage battery and put that in too, Mercedes uses these large batterys and places like auto zone sells decently priced replacements. Sctty

[bluebeltatt]

haha this guy is awsome! sounds like joe pesci, gotta love him!

[canoeshoe]

this dude is badass, he cant work on everycar so please be considerate!!!!!

[scottykilmer]

@0penminded2u Well, I just worked on a VW and a Benze yesterday. Basically, they are giant overengineered :POS made by Germans with an anal complex with their machines. If you're dumb enough to buy one of those vehicles, don't try working on em yourself, they are too complex and require too many special tools and computers to recode software when changing many parts. Only a complete ass would design such vehicles. I'm showing how to fix normal vehicles here. Scotty

[0penminded2u]

@scottykilmer

A Man of my Kind. I have owned a auto repair shop for over 20 yrs. And i agree w/ you 100%. Everytime one of those POS German Over rated cars come in, My blood pressure goes up. And the people who own them are just as bad, I would take a lexus over any Greman over rated pos. Thanks for the repile.

[smithraymond09029]

@scottykilmer LOL, well said Scotty!

[crazeeluke]

@scottykilmer OMG i love this comment.

[Antimortem]

@scottykilmer so what about korean cars? i drive a hyundai and its 213,000km on the odometer. i 'd like to know your opinion since you are a great mechanic.

[scottykilmer]

@Antimortem I'm not a big korean car fan. they are somewhat cheaply made and parts are hard and expensive to procure. Scotty

[panzerveps]

@scottykilmer I find the german cars very easy to work with.

but it's all habit and special tools. but every once in a while i come up with some random swears targeted at some random german engineer named hans or fritz...

[DeafJustin]

Wow I love your blog mean I am enjoy watch you

Justin

[Matthew55904]

cant u just use one of those tools u plug in under the dash to check the electrical system?

[scottykilmer]

@Matthew55904 No, they are not that accurate, they only measure voltage, you need a lot more tests than that. Scotty Kilmer

[kriskinealy]

Man this guy cracks me up

[PUREAAMERICAN]

Also an alternator can have a shorted diode which will leave you with a dead battery overnight, yet the alternator may still charge the battery and run at 13.8 VDC you can test with ammeter in series with b+ terminal. Likewise an alternator may test good when it is cold yet when the underhood temps rise the voltage regulator malfunctions and the alternator has no output, misdiagnosis is common in a failure like this.

[scottykilmer]

Ah yes, nothing is more annoying than intermittent electrical problems. That's why I love purely mechanical jobs best--you see something broken and replace it. And of course, with any electrical work, there's always the possibility of an electrical problem further down the line in the circuit that can yet again destroy a new part you just installed. Isn't being a mechanic fun! Scotty Kilmer

[dnl5649]

thats whats happening with my car. i have a 77 mercury cougar.

the alternator's amp meter reads 13.8 volts exact at 10 amps.

im like wtf!!??

i took it apart and put in new brushes still 10 amps.

i checked the diodes and somehow the solder joints were loose and arcing.

so i have to take it apart again and resolder them so i dont have to get a new alternator

[scottykilmer]

They are called alternators because they generate alternating current. Inside them, are tiny diodes, which change the alternating electricity to direct electricity for use in the vehicle. It may sound strange, but it's true. Perhaps AC/DC should write a song about it. Scotty Kilmer

[dnl5649]

that would be funny if you crawled in the back of the mustang and couldn't get out.

do you thing i should replace my diodes or should i just resolder them back in there properly.

the solder joints came loose and are arcing in the alternator

[TheDigitalguyy]

I was under the impression that alternators make DC current

[SWD2263]

when disconnecting the vehicle battery to do work, some people say to plug the 9 volt battery into cigarette lighter to keep radion memory and car computer stuff.. is this necessary? I've never done it and had no problems...

[scottykilmer]

Yea, some guys who are fanatics will do that. Some modern cars have so much computerized crap on them, they don't want to reset it all, and they will do the battery trick. If you don't thougn, it will do no harm to anything other than those stupid electronic memory based systems, which you can just reset. Scotty Kilmer

[TranceScene]

The intro audio sounds out of both speaker channels just fine. After the intro, the audio comes out of the RH speaker channel only, but I can still hear it just fine.

[scottykilmer]

Yes, as I've said, it was a TV shoot I did, and one channel was used for me, and the other for the narrator. So if you can't hear anything at all, then your right channel in your computer is messed up. Scotty

[michaelheiland123654]

Thank you for the information!

[Rhin0Neil]

NO SOUND !

[scottykilmer]

It's got sound every time I try it on every computer I've used so far. I don't understand it myself. and as you can see, other people are making positive comments on the video, so it's got me stumped. Scotty Kilmer

[JohnoStudio]

I cant hear your voice either, even when i select 'high quality'. I hear the intro of your clip but nothing after that

[scottykilmer]

Something must be wrong with your speaker system. I just played it again and it works perfectly fine. Mind you, it's stereo sound from my original TV segment, and the voices change from channel to channel because we used one mike on me and one on my commentator. Scotty Kilmer

[Duratec86]

Do you have any suggestions as to prolonging the life of the alternator? I have a 2000 Ford Taurus w/the DOHC engine, which makes changing it a major ordeal (drop the subframe, etc.)

[scottykilmer]

Yes, be SURE the battery is in good condition and replace it when it's getting low. I personally use a Midtronics tester which tells the battery state in about twenty seconds of testing. When it says replace, even if the car starts OK, I replace them, so the alternator is not strained from a weak charging system. Scotty Kilmer

[h2oandbeyoud]

NO Audio, Whats up with that.

[scottykilmer]

It worked fine every time I checked it out. Be sure to click on the HQ high quality button on the bottom right corner of the youtube panel below the video. That way you'll get high quality picture and sound, which works much better. I have noticed that sometimes right after putting a video on, which I just did a few hours ago, there are sometimes problems that get ironed out as people watch them. Scotty Kilmer

[rax2099]

thanks