GM 3 wire alternator diagnose / troubleshoot HIGH VOLTAGE 10si

just an idea on diagnosing a HIGH VOLTAGE reading on your GM 3 wire internally regulated alternator
truck is a 1980 Chevrolet C30 "custom deluxe" cab and chassis dually

i have many alternator videos but feel free to ask me anything

[flipeecupsstuff]

You saved me a lot of trouble! Your no BS approach is super refreshing, and earned you my subscription. My dirty connectors left me stranded with some intermittent bullshit, no clue why I hadn't thought to clean them.

[markschofield]

Excellent video- thank you for the no B.S. format and straight forward instruction!

[closekutt]

I had that same alternator overcharging problem about 3 weeks ago, driving along and the cab filled with white smoke opened the hood and my battery was steaming from the vent ports and melting. I almost made it to the auto parts store, but it burned the battery post clean off and melted the top of it, they took it as a core. I needed a new battery and alternator... lucky it didn't melt any wires, but I rewired the harness afterwards just in case, great video man....thanks a lot....

[johnjohnson]

On my C-10, installed a new gel battery and the alternator boiled the gel inside the battery. Took it right back to the store and they said they have never seen that done before so it must have been running very high. Picked up a new alternator while replacing the gel battery. Great tips on checking that!

[kevinlowe]

Chris I watch all your videos, keep them coming

[frankgualtieri]

Hi brother, charging too high is usually the regulator in the alternator . Yup it will boil the battery if its too high . If its not charging enough, usually the diode trio inside . Liked your video cheers from Canada

[dylanmorse]

Chris: Drops f bomb
Also Chris: shi... crap

[BlueGooseGarage]

I had one blow the headlights on my car once overcharging like that definitely not fun good thing you caught it

[gtmotorsports]

Hey Chris,
Love your videos and your channel. Been subscribed for a week and have watch a lot of your electrical videos. Keep up the good work. I got a question about an alternator swap I did.
I have a 67’ C/20 with a 350 that I converted to an internal regulated alternator from the external alternator. I followed your video on how to rewire it with a 194 bulb on the ign side. My internal regulated alternator was used from my stash. It will only charge 13.25 and the 194 bulb won’t go out. It dims real low but never shuts off unless I turn the key off like it supposed to. No local parts store will test the alternator. You think it’s bad?

[moshewakatelutiw]

Thanks for making a video that's easy to understand.

I'm working on a cadillac that had a failed alternator but is still not charging. I think the excitor wire isn't getting power. Should it have around 12 volts when the key is turned ..
thanks..

Also...overly high voltage will burn the battery...I do know that

[jeffmencer]

Put new regulator in mine, easy to do. Still overcharges to 16 volts. Replaced plug and everti e sense wire touched to battery voltage it would start shooting up to full charge 16 volts

[billygreenhorn]

Bad voltage regulator. I'm surprised you didn't take it apart and rebuild it. Great vid.

[artieartieartasmr]

external Alt.. Drain at alternator hot lug & I'd been working/stuck trying to fix it the right way at 2 weeks. I could have gone thru ignition wire as you illustrated but I put a toggle switch just to move on & have time to think about the problem? Thanks you & I'll check with you later.. U"ve some nice tutorials etc.

[baldovaldez]

Voltage regulator some old chevys have separate regulators on the core support and you have an adjustment nob on it if the voltage is too high it can burn your head light wires I fond out the hard way😁

[joesdot]

Definitely would have cooked all the acid out of the battery..
That I know fur sure!
Great video!

[longBowHunterII]

my only added tip I would check voltage right at the alternator connections. 14 volts, diode is bad.

[richiecasuccio]

Never shoot anything you’re not going to eat unless it’s a rattlesnake but yes that would cook your battery !alternator is a supposed to range between 13.8 and 14.2

[normhodgkinson]

i agree about the bird and cat. it is illegal to shoot a cat or dog. if someone shot one of my cats, i be ind handcuffs. glad you got the alternator dialed in.

[Squares.SSs.and.Bowties]

Hey! Thanks for the video, Bud. For real. Anyhow, reason for this comment is regarding a statement you made in the video. You mentioned these trucks are only wired for 75 amp max. I too have a few squarebodies. I am setting one up with a meyers plow and was going to put a 94a 12si in the truck... until i heard your 75 amp comment. Can you please email me (or however this works) some info on that limitation? Thanks a bunch! Also, no need to check- I did like and subscribe. For sure!! Thanks again. Take care!

[thomasinzana]

At 8:15-8:20 after installing the new alt and starting the truck, what is sparking under the steering column? Could it be possible that alt you uninstalled is a 73 amp alt? Resulting in a higher output...
I used to hobby car audio i know i used to purposely look for a factory alt that had a higher output due to the power draw of the amplifer when the bass hit... just throwing it out there but another possibility would be someone ran the truck with 24v and the alt is/was really weak only charging at 16v at idle... most alts do a minimal charge until the rpm's are raised or under load... not sure if you're aware or not but some digital battery chargers also offer an alt test feature excluding the use for a multimeter