Starter Circuit Voltage Drop

[kneedown4GOD]

great vid,you really simplify the voltage drop test.it sometimes takes time to wrap your head around it but once you do, voltage drop can really be a life saver.

[505197]

Volt drop tests are intresting, mainly due to the fact there is no "standard" . How many volts should I see drop between the alt and the battery? How many tenths is ok and at what point is it too high? I read .2 volts for a 70 amp output and kinda go by that as a standard. Resistance generates heat, how many bad cables have you found just by feeling a terminal? I saw a Japanese guy workin those multi-meter probes like they were chopsticks, man was I envious, he was precise as could be

[Juusstas]

How he got 12V between +starter and +battery pins at the beggining, if at the end he realised, that voltage drops between clamp and wire's washer? If the starter got 12V at the beggining, so what is wrong? car should start up normally. Am I right?

[ttcautotech]

@Juusstas In the video we are using the direct method of measuring voltage drop. One lead is placed at the beginning of the circuit (B+ at battery) and the other is placed at the other end of the circuit (B+ at starter). Any voltage lost between the B+ and the starter B+ will show directly on the meter. We are not measuring voltage to the starter! Since both our meter leads are on the B+ circuit the meter will show the total voltage lost in the B+ circuit. We had 12v at batt but lost in circuit.

[donkason]

Simple and easy tutorial on what can be an elusive problem. Thanks a lot fellas!

[TruthBomber]

Thanks for this video, I like how you didn't gloss over anything, but showed exactly where to probe for each different portion of the circuit. Very well explained. I was able to methodically pinpoint my problem area as the interface between ground wire and clamp. Put a new clamp on, cleaned the wire, and solved a very frustrating, intermittent problem. Thank you!

[DusterMtnEX]

I just want to say thanks for this video. I've spent days reading electrical mumbo jumbo trying to learn about this and other concepts of testing DC systems. I've learned more here in 6 minutes than I have learned in the last 6 days.... Now if I could just understand how I can have enough supply voltage to a good coil but not enough flow/current/amps to make a nice fat spark instead of a skinny orange spark....

[freshXtuna]

NiCE thanks :)

[scootbmx01]

its the ground, same thing happened to mine

[ttcautotech]

@scootbmx01 Hmmm, did you actually watch the video? lol. Voltage drop is measuring the voltage difference between two points. ie. wherever you put your two leads. In this case the meter read 12volts. That meant that the difference in voltage between the clamp and attached eyelet was 12 volts! Since these two points are touching they should have exactly the same voltage. They did not! Notice it was the POSITIVE Clamp that had the voltage drop between the clamp and the eyelet..

[scootbmx01]

@ttcautotech i was just listening to the clicking sound, i had the exact same sound, grinded my negative post and clamp and it worked fine :)

[ttcautotech]

@scootbmx01 Ah yes. Voltage drop on the ground, while not the problem in our case, would cause the exact same symptoms. A bad connection on either could cause the starter to just click.

[xexorz]

Excellent Video - Great diagnostic technique! For those who want to know more about the Maths, look up "Ohms Law" to learn about voltage drop across a resistor (which is what we have happening here - the bad connection is effectively a resistor (all-be-it a potentially intermittent one).

[PineCreek4x4]

I wish all electrical repairs were this easy. Nice job though. Not many techs even know what a voltage drop test is...

[jschirr]

absolutely one of the best videos on voltage drop i have seen on youtube. great job!

[RescuePits1]

Wow, very informative video!! Thumbs up!!!!

[gzimca]

Hvala majstore,odlicno obavljen posao. Sir,thank you so much,excellent video.

Keep sending us more. Your accent is so charming,you sound like John Wayne-The Duke. Regards from serbian mechanic.

[vrbas100]

That video is great and I said I agree with the comment of @mindswapp.

[vrbas100]

komentar koji je postavio @mindswapp je potuno u pravu otpori nisi isti na 15 ampera ili 150 ampera U svakom slucaju pad napona od 1,5 volt iukazuje na error Ne sporim da covek ne zna sta prica ali FLUKE ili neki drugi instrumenti ne prepoznaju stanje opterecenja , sto moze majstora da skene sa pravog puta prilikom uspostavljanja dijagnostike U svakom slucaju ovaj snimak je i poucan i za svaku pohvalu GOOD VIDEO

[ttcautotech]

@vrbas100 My Serbian is not good. Are you saying there was an error?

[yourtheace]

good video, I think this will help me solve my starting problem

[mindswapp]

Coulldn't you do the same thing with resistance testing for bad continuity? Nice info.

[ttcautotech]

@mindswapp  In the case of high current circuits like the starter, resistance can not be measured accurately enough with an ordinary meter. For example, .01 ohm sounds like a good connection. However, if the starter is operating at 150 amps this resistance would cause a loss of 1.5 volts! Think of it this way, resistance is a static measurement that tells us the circuit is there. It does not tell us how much current it can carry. Voltage drop is a dynamic and true test of the circuits operation

[spelunkerd]

Nice to see an example of clear thinking, applied practical science.

[clcautotech]

Good job guys. I'm showing this to my students as a back up to my lecture and demo.

[bandilangpilipinas]

A Certified Technician!

[frogca]

If you're a dishonest mechanic you could jack the customer for about $500.00. Great video and a perfect example of how knowing electrical theory can make you a lot of cash.

[Echo205]

on what setting did you have it on? oh yea. nice vid

[MrHvm1985]

One of the best explanations i've come around..not even in school did i see something like this...i'm taking my ASEs this coming may 2010..I know this is going to help me..Thanks for the video, looking forward to more..

[AutoTechHector]

@MrHvm1985 I couldn't agree with you more, There is a lot of voltage drop questions concerning the starting circuit in the Electrical ASE test. You wanna learn voltage drop... this is it right here!!!

[REDTEAM22003]

love for you guys

[DCrepresenter]

Very good video.Hopefully I'll be getting my ASE soon

[munoz1051c]

you have a very clear and thorough way to explaning things like this. great video!

[ufoseverywhere]

good job! need more tutorials like this. expert village blows cock and balls and swallows

[grazzy2]

Best explanation seen to date. Good job guys.

[jheetman]

great video, i drop test before checking voltage at accesories, much faster to find problems that way. just remember that the cicuit HAS TO BE LOADED to check the drop in voltage.

[bluebeltatt]

very good tutorial i use dielectric grease on just about every electrical circuit JUST to be safe .

[HondaMasterTech]

I would have performed the diagnostic exactly as shown. Cant tell you how many debates I've gotten into over the benefits of grease on electrical connections.