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

[@flipeecupsstuff7632]

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.

[@markschofield9361]

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

[@johnjohnson807]

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!

[@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....

[@chriscraft77022]

what the heck!!!!!

[@kevinlowe4845]

Chris I watch all your videos,keep them coming

[@frankgualtieri3966]

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

[@Mike_Can_Fix-it]

Exactly. How that went from that to a new 'Nator. And how did you know that bird was innocent? Maybe it was a jail bird

[@robertolira8331]

You’re the best guys! Thanks!

[@dylanmorse]

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

[@joesdot3288]

Who do we call to report him, his wife? 🤦‍♂️ 🤭🤭

[@dylanmorse]

@@joesdot3288 bruh it’s a joke

[@joesdot3288]

@@dylanmorse dude I know... lol.. It's all good have a 🥃 on me! 🤠👍

[@jeffmencer9473]

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

[@panchoveliz1098]

So what ended up being your problem then?

[@billygreenhorn9275]

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

[@davisconner240]

Instablaster

[@chriscraft77022]

i used to do that when i was young... the truck is going to be a driver so i need to be able to pull into oreilly and switch it out if it goes bad in the future..

[@GinaMorris-mn2vp]

​@@davisconner240 😊😊😮

[@BlueGooseGarage]

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

[@zemoney954]

Great video, thanks for info

[@moshewakatelutiw6233]

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

[@artieartieartasmr6407]

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.

[@gtmotorsports937]

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?

[@bolawdean]

Love the no nonsense

[@danielesilvaggi]

Good to know nice video thank you.

[@longBowHunterII]

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

[@baldovaldez3339]

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😁

[@ricardoserrano8270]

My alternator still running high voltage and battery in my older Chevy any tips just replace my voltage regulator and alternator

[@baldovaldez3339]

@@ricardoserrano8270 did you adjust the voltage regulator it has an adjustment knob

[@richiecasuccio2497]

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

[@sarahgreenslade3283]

Thank you SO MUCH!

[@ronsteezley]

nice new intro

[@joesdot3288]

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

[@normhodgkinson6965]

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.

[@chriscraft77022]

the owner is cool but he is from mexico and has his drinking buddies over every day.. they shoot guns all the time (real ones in the houston city limits) ... i could care less but i think about my cats and my cars getting hit.. when i said that i saw his head peek over the fence but his buddies obviously dont respect him.. i will make a video if i ever have to go over there..

[@mystic24100]

I just had my 10si start charging 16 volts. I unplugged #1 and#2 2ires, now it doesn’t charge. I will check it later, but didn’t want to run it that way.

[@artieartieartasmr6407]

New Alternator is goo, charging fine, but still have voltage drain?. Auto Zone says to run with external regulator O. G= old wires? Bought new regulator need to install (Later) to see if that may be the problem I'd like to keep the gauge intact. let me get back to you shortly? Thank you Sir.

[@eddyherrera6326]

Bout time someone gets hands on

[@adamgarcia1824]

Best part was when you told Neighbors off

[@Rollin_with_geezy]

I have a 220 alt and a brand new battery and voltage is failing and killing the battery what can I do it be ?

[@thomasinzana273]

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

[@chriscraft77022]

that is a little shiny string (like party decorations) .. I seen it while editing and thought the same... truck is all original and probably the original alternator.. thanks for the info..

[@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!

[@chriscraft77022]

I have a 100amp alternator upgrade video

[@Dom_gon4]

Whats going on bro, I have a question, could you do a video where you find top dead center? I’ve been having trouble with getting my motor to fire up again I had taken it apart to put a new Cam in but now that I want to start up I can’t seem to find TDC, what’s your trick? No one has made an easy to follow video and you go in-depth!

[@chriscraft77022]

I have one.. it’s a little confusing but it works

[@normacalderon3503]

Hi If I have to buy those wires are they all the same voltage?

[@brentalexander3459]

Why why why. I put new alternator on my 84 olds cutlass and when key is off charge light stays on and before I changed it the light was dim with old one. Also my tack in gauge cluster is maxed out but when I turn key light goes out and tack drops to 3/4 bout 4 k hmm

[@larrybroad8746]

hey chris i am putting a new engine into my 1970 el camino and my 3 wire alt wires got messed up dont know what goes to what except the eyelet 1. can you tell me from looking behind the alt where and what color goes into what post dose that make any sense to you.

[@chriscraft77022]

I have a 3 wire gm alternator hook up video

[@fastlanebruce]

I am about to use the 12v ignition system on my 83 caprice

[@chriscraft77022]

your car already has it

[@ljschaerig2134]

I have bin having a high voltage problem on my 1990 Chevrolet Silverado k1500 I’ve replace my alternator 3-4 times I would use my truck and if I turn it off and try to start it again right away it would kill the battery I’d have to let it sit 20-30 minutes before starting again and it’ll start. Recently just bought a new battery doesn’t do that now I can turn it off and on no problem but high voltage is still there and I’m still trying to figure it out seeing this video I’m gonna check out my wires and the fuses on the fire wall I got new control module still need to put that on new ignition coil that fixed my starting issue for while and it just started happening again but yeah new battery everything is fine but high voltage.

[@chriscraft77022]

you might have plug on backward .. jump terminal 2 to battery

[@INTERNA9]

Thanx

[@robertolira8331]

Buddy I think the voltage regulator built in the alternator is bad on the old one! I got a question: will a 1500 rpm enough to make the alternator charge?

[@chriscraft77022]

they start to charge at 500-700 rpm if they are wired right.. a 1 wire may need an rpm boost up to 2000 to start charging but should start around 1200 for sure

[@tonyscarcare5657]

What would make a gm 3 wire alternator drain the battery? I tried a new one and it shows a drain as well. Kills the battery in two or three days. If I eliminate wire #1 the problem goes away. Thanks!

[@chriscraft77022]

Watch my gm 3 wire hook up

[@tonyscarcare5657]

@@chriscraft77022 thanks. I did watch it but I've already put a diode in there and it still shows a drain.

[@reysauto-repair7672]

chris i have a 1972 chevy chargung system is over charging put it out 16v has a new alt and a new voltage regulator any idea of what could be making it charge too high it has an external voltage reegulator

[@chriscraft77022]

adjust the regulator

[@reysauto-repair7672]

Ok I will do thank you very much Chris

[@artieartieartasmr6407]

Oh? & I like the truck=Nice. But didn't know it was your show cuz it was off subject &? Well=Your Other videos are straight on topic without sidetrack in content & I've watched too many of those & they do have value but I'm egore to get too the point so I can get mine fixed?

[@chriscraft77022]

not this video... gm 3 wire hook up.. its old from 2016

[@michaelduncan3206]

Overcharging will cause battery to swell up

[@thingsinlife]

If you wanna save some cash, can get the voltage regulator for about $15 from Rockauto, Summit etc. AC Delco D680, that one is a GM certified OEM replacement part. Standard Motor Products do a V111 which is about $1 cheaper but for the cost, I'd go with OEM certified.

[@chriscraft77022]

I used to do that when I was younger..: when they used to keep parts like that in stock ( like 20 years ago )

[@thingsinlife]

@@chriscraft77022 Ye that's a good point, sometimes it's more worth changing the part put same day, than waiting several days for a repair item to get sent out. Thanks for the helpful vids

[@altpotus6913]

Thanks. I have the same problem. I'll order a regulator.

[@404_unavailable_69]

Wasn't there a way to full field these alternators for diagnostic purposes? Maybe someone did that and left it . Idk . Great video tho 👌

[@chriscraft77022]

im not sure im not a mechanic or auto tech....

[@MrMrsregor]

Is 14.99 volts at idle too high ?

[@chriscraft77022]

no. i think 15.2 is max.. but that is a HIGH reading for sure.. is everything hooked up?

[@MrMrsregor]

@@chriscraft77022 yea. Everything seems to work fine. I’ve just never seen anything over 14.7 and mine is 14.99… my electric choke is not working properly and I noticed the voltage while testing the choke… Thanks for the reply and helpful video! I think it is illegal to kill song birds in most places (but im not sure what species are technically a “song bird” .?..)

[@johnfry9010]

It will boil your battery .

[@donaldolmstead8350]

40 bucks and 15 minutes you could have fixed that alt. Internal volt regulator was most likely bad. I run car audio and it seems it’s always the problem.

[@chriscraft77022]

I used to do that when I was 15 years old. I’m 37 now and prefer to have a lifetime warranty on the alternator

[@longBowHunterII]

it would have over cooked the battery and electrical components. over charging could blow the battery.

[@artieartieartasmr6407]

I watched but it didn't give me much on voltage drain or regulator jumpers? I guess to think & sleep on it & hopes it & will fix itself? Sometimes things do that or I'll sleep on it a few more nights then go smash the windows out of it then have too fix that also=LOL?

[@Mike_Can_Fix-it]

Why couldn't you just loop it back to the + post on the back of the alternator? No fuse, nothing. Just a 6" loop

[@chriscraft77022]

why not just rewire the whole thing like a tractor? I have videos on that.. you keep the factory wiring factory..

[@reneprovencher8395]

My 69 corvette, new m/rebuilt alternator . It’s a one wire. So I only have one wire run to starter. I start the car up. Dash meter shows charging. What’s sobbed that I have a brand new battery running. After awhile engine dies. Battery dead. It it because I didn’t run a wire from the alternator to the switch? I pull battery and engine dies right off. I don’t have comp or. Nothing just an old 69 corvette. My new WiFi g harness had only one wire to the alt. But alt shows like yours a place for the two wires. Oh and go kick those dumb ass kids. Damn killing birds, then they kill cars and dogs. Ugggg thanks for your videos. I got carried away when kids shot the bird. Ok I pull battery while engine running at it dies. Best with me I used to bd a licensed auto mechanic. I’m very old and I actually have forgotten everything I know. This is the last car I’m Messing with. After seeing your stuff I think I bought a bad alt. Thanks China for a f’ing 149$ bad alt. I’ve kept it all winter not installing it, return policy is nope!

[@chriscraft77022]

those were grown men shooting the birds.. there are too many things that can be wrong.. you need to make a video showing it the best you can.. I have no clue if you have original alternator? internal? Externally regulated? are you running a voltage regulator? whatever it is it can be solved in minutes but you might have to watch through my older videos.. not this one.. the videos on my 70 Chevelle.. I know everything about the wiring on GM