How To Wire A Vintage GM 3 Wire Alternator

A simple method for restoring the charging system on your old 1960s-1980s GM car or truck, or how to wire an AC Delco alternator to your marine boat or farm tractor. I show you what wires do what and where to make easy connections for power and grounds.

[@dougmeador6364]

Great video thank you. Very helpful question. I installed the alternator on my 55 Belair and it gets crazy crazy hot and will start to whine. There is really no load on it to speak of and the battery is new. I'm going to ground it now to see if that does anything but I doubt that will change anything. Maybe a short somewhere? I pulled the 2 pin plug just to see what it would do and it cooled down and the whine stopped. Not charging of course. Any thoughts?

[@American-OutdoorsNet]

Thanks for watching. In this day and age, I have learned that new doesn't always mean better. My first thought is to verify the alternator and/or the internal regulator is functioning properly/charging within specs, especially if the alternator before this one wasn't noisy. Check the output but if nothing else shows up, I'd consider changing it out; at least with a used unit for confirmation.

[@skinnyway]

my 82 C1500 has a single red wire running around things (thank God its just one!!!) but plenty of rat chewed wires that need repairing. One of which is on the alt. I will come back and finish this video - out of time now. I hope you address my needs. I used to have a 71 dual headlight GMC. loved it. it got stolen. finally got back into an older truck.

[@American-OutdoorsNet]

Thanks for tuning in. GM truck wiring is a sugar cube for rodents.

[@johngillon6969]

Thank you , I am not a mechanic, but I have been driving over 50 years and have never taken a car or truck to a mechanic. Way back when i started driving my world was full of wrenching brothers, but over the years they all disappeared, I want to consider you a wrenching brother and subscribe and will watch every one of your videos. I have an alternator like this in my boat and have been trying to figure out what you taught me today. Thanks a million.

[@larrywillbanks8935]

Thanks my freind had forgotten how to wire mine up

[@sammyvices2547]

Just installed one of these on a 64 Ford galaxie. Got rid of the old generator. Thank you for your video it’s gold

[@American-OutdoorsNet]

I appreciate the good word and thanks for tuning in.

[@BeardedGiant79]

I really appreciate this video! Well done, great personality and very well articulated!

[@American-OutdoorsNet]

Thank you!

[@donniegoble5685]

THANKS THAT WAS VERY HELPFUL I AM WIRING 78 CAMARO ATERNATOR UP THIS IS PRETTY SIMPLE METHOD

[@jshukmeister]

This was an EXCELLENT video! Very helpful for converting an old Case tractor from generator over to alternator. Thank you very much!

[@American-OutdoorsNet]

@@jshukmeister thanks for watching.

[@noahenright3082]

This helped so much, great informative video thanks!

[@American-OutdoorsNet]

Glad to have been an assistance. Have a great weekend!

[@martinduwors8632]

This was really helpful in building my engine stand. Thanks so much.

[@kevinbresnahan3394]

I'm wiring up an old straight 6 Chevy in a t bucket, you helped me out, you're a good teacher. 👍.

[@conniemorris9025]

Thanks for the video . I'd like to replace the one wire alternator in my 1950 GMC pickup with a 3 wire . A good demonstration on how it works.

[@American-OutdoorsNet]

Thank you.

[@mikealdag7309]

Thanks for the video , simplified my project right now.

[@glennmiller9031]

Thanks. Facing wiring one in to my 62 Chevy C-10 resto. Glad to find this, Very helpful.

[@JayCee_1014]

Great video thank you gotta learn the systems to never be stuck while traveling in these square bodies

[@miketuch]

I have a 95 S-10 2,2 L Auto, CS130 alternator with PLFS connector. I have watch dozens of alternator videos - this is far and away the best alternator video to get your 80s/90s vehicle running. I was losing run/start through the dash PC board. This video will show you how to duplicate that circuit.

[@American-OutdoorsNet]

Thank you.

[@krstoner53]

Great common sense video on this subject. Off subject maybe you’re in southern states and don’t get much snow but your trusses seem a little far apart for the pitch of your roof. My building is similar pitch (12-3 ?) and width (24’)as yours and engineer at local truss factory said I would need a 2x6 on the bottom of the truss instead of a 2x4 like yours appears to be since I was spacing them 3 feet apart instead of 2. Yours looks to me 3 or 4 feet apart. I guess this depends on region or location where they’re being used.

[@jarrettslee1]

Awesome! Best video on this so far.

[@American-OutdoorsNet]

Thank you. I appreciate it.

[@fredolshove2498]

Great video. You made it simple to understand. I have that alternator on my 78 corvette. I just added an electric choke carb. One video I watched said I can run the power to my alternator. But the video was for a ford. Would I run my hot wire to the number 1 post then for the GM alternator? Thanks you for your time. Fred

[@80fordmustang6]

Thank you for explaining bought a 59 fairlane that’s been converted to this system and wanted to make sure it’s wired correctly

[@fourfortyroadrunner6701]

This info in this video is WRONG

[@badwolf1795]

I have question.I have a Mercruiser 140 inline 4 Chevy motor. I installed a new alternator that only has 2 wires. Battery+ and ground. The old alternator had 4 Wires going to it. I taped back the other wires from the boat and used Bat+ and ground on the new alternator. I measured the voltage when the engine was running with a meter and its charging 14.4 volts or so. I can turn off and on the engine no problem. My question is would one of those wires from the alternator I did not use go to the key? Would accessory's run off the alternator while running ? Newer alternator does not have a 2 wire plug. I assume because I was getting 14v at the battery. Thanks

[@fitzpreacherfarm6826]

Very good and simple video. Much appreciated!

[@ICTMike-c8k]

Great video one of the easiest to understand

[@danielw.5993]

Thank you soo much sir!! Great content

[@youngjj757]

I ordered an alternator it's the 1 wire kind would anything happen if I hooked it up the way my old alternator was before I removed it?

[@russellnorton9940]

thankyou thankyou very much from canada, you made it look easy and i appreciate that, i have an old ford 2n tractor im converting from 6 volt to 12 . i installed the same alternator as the one shown here, you made it easier for me now. thankyou

[@fourfortyroadrunner6701]

Info in this video is WRONG

[@russellnorton9940]

@@fourfortyroadrunner6701 your correct

[@bamatractor]

The wiring was very accessible!

[@ishaw763]

Great video. Lots to learn

[@fourfortyroadrunner6701]

This is NOT a great video. Info is WRONG

[@ishaw763]

What's wrong​@@fourfortyroadrunner6701

[@DavidFuentesFWTX]

Great video and description of the wiring. What gauge is the ground cable you added at the end? Thanks!

[@American-OutdoorsNet]

Thanks for watching. Cable is 6Gauge.

[@jasonerb2577]

I picked up an old Ford 8n tractor. This is the third N-series tractor my family has owned in my lifetime. We had an 8n when I was little, then a 9n when I got to high school/college, now I picked this 8n up about a month ago. I'm not sure if the original 8n was ever converted to 12v, the 9n was. When I got this home, I found that they had hotwired it enough to sell it. It was a real mishmash of 6 and 12v parts, mostly all bypassed and a fried condenser because there was also no resister or anything else in use...it was a mess. These old Fords actually take a GM alternator because they fit in the mounting brackets available. Most guys use a single wire alternator for ease of installation, but I was thinking about wiring up a 3 wire alternator (the fit is the same) for longevity, but I haven't seen anything about hooking one up to one of these tractors. This puts my mind at ease. These basically hook up almost identically the way the old generators did (minus the exterior regulator). Thanks for the video, and keep up the good work.

[@American-OutdoorsNet]

Great story and thank you for watching.

[@jerryhaggett2391]

Good advice thanks.i have got use 10g to run from the alternator on my puegout diesel as the loom heavy cable broke the copper tab connector. Thanks hope it does nt confuse the e c u

[@tomference4618]

I am confused now,..please wink at my ignorance. I would like to install an "ammeter" in the #2 line before connecting to battery positive. And I would like to have a warning light in the #1 line, but don't know where to connect the other side of it. ???

[@No1Beaver]

Thank you. Great video!!

[@skipwilson5086]

That was a SI Delco Remy alternator I'm thinkin' , Can you do a CS for us? Very good, plain, simple explanation. I liked it alot. Thanks it was delivered good too...

[@fourfortyroadrunner6701]

Except the wiring depicted in this video is WRONG

[@guyprimo6414]

Extreme simple great job buddy

[@enriquerodriguez1804]

Thank very clear and precise information, and video . 👍💯

[@American-OutdoorsNet]

Thank you.

[@garrettwagner8880]

I just absolutely love your intro 😂

[@garyboase7981]

Thanks, exactly what I needed to know.

[@therollingstone5495]

Hello. Very good video, informative and well illustrated. Hopefully you can help me with my problem. I just replaced a non working Delco Remy 10SI with a 22SI on my 1995 Cummins 8.3 (RV). Before the replacement, I was getting 0 voltage output and my tach was all over the place. With the new alternator, voltage output is 14v but now my tach doesn't work at all. Did I miss something or is the tach gauge not working? Is there a way to test for a tach signal from the alternator? Thanks

[@jerrellschevy]

my alternator on my 72 Cadi has the ground run to the battery, is that normal, or should I remove it and run a ground from the alternator to the engine block?

[@onetransmission7871]

Older Cadillac used to have a ground strap from the outside starter bolt to the frame. 10" to 12" flat braided cable.

[@billysmith1644]

Hi, great video. Very helpful!!! I have a question as my battery is in the trunk of my hot rod..... Can i hook this to the starter as u said. You didnt talk to much about that. So just wondering if the battery will still get charged up! Thanks very well done!!!!

[@robertgeary7520]

Great video 👍

[@jamestregler1584]

Naa , dad gum it ; I'll stay with my generator 🤣🤣🤣 Thanks from old New Orleans 😎

[@garryharris9098]

Thanks, I have done this on old tractors what if your plug has 3 terminals. I have one with a 3 wire plug like that on the side and one with a 2 prong on the back of the alternator.

[@thisisyourcaptainspeaking2259]

The third terminal is probably connected to the #1 spade, there were several iterations of regulators available for various reasons. I believe your 3rd terminal was intended to power a low-current accessory such as a lamp or small heating element such as a carburetor choke heater. There were are regulators available for 24V systems and several voltages available to better match the intended vehicle use, such as a taxi-cab that runs all day and night, the regulated voltage was a few tenths less to extend battery life (avoid slight overcharge that can benefit short duration but extended duty will cook the battery too quickly). Those regulators were around 14.4V and 14.1V, if I recall.

[@ChancyRoyal]

Excellent video

[@American-OutdoorsNet]

Thank you.

[@fourfortyroadrunner6701]

Info in this video is WRONG

[@fourfortyroadrunner6701]

You can also replace the internal regulator with a "one wire". These do NOT NEED the no1 circuit. Some "one wire" regulators seem to "like" having no2 connected (sensing) and some do not seem to care

[@markbovey9786]

Great video. Thank you.

[@American-OutdoorsNet]

Thanks for watching!

[@azmadnesshustle]

Thank you this really did help 🤙

[@American-OutdoorsNet]

And thank you for watching.

[@thomwessels2281]

So what gauge is used for #1, the exciter terminal that's only?

[@thisisyourcaptainspeaking2259]

Correct! I do prefer to connect the sense wire (spade #2) directly to the battery positive terminal as opposed to the alternator output post. The reason is, this way the regulator is sensing battery voltage directly, and it compensates for the slight drop that occurs between the alternator output and the battery. Incidentally, the spade #1 (excite) regulator terminal can be connected to your electric choke heating element to power your choke heater. In this case, removing the internal alternator wire-wound resistor allows you to use your alternator idiot light to monitor the choke heater element. An idiot light that fails to illuminate during key on bulb check indicates the choke heater may have failed

[@American-OutdoorsNet]

Thanks for watching.

[@guylipsky3599]

The problem I see with this that red wire you took from plug to the battery wire will always be pulling amperage when check on the negative post on the battery

[@fourfortyroadrunner6701]

No. The no2 is designed to be connected that way. However, wiring no1 direct to switched 12V IS WRONG. Info in this video is WRONG. USE A DIODE OR SERIES WARNING LAMP or you will eventually fail the DIODE TRIO

[@kern_yak_angler]

Great video thank you

[@fourfortyroadrunner6701]

No it is NOT. This wiring as depicted is WRONG

[@sunspiral79]

Isnt there fusable links somewhere in the wiring?

[@American-OutdoorsNet]

Typically next to the firewall junction block near the power brake booster but after 50 years they tend to be MIA. They are easy enough to add.

[@rosemcbirney5123]

Stater wire which one is that as I won’t to use for electric choke

[@ivandhotmanvilliers3361]

Great explanation

[@canalm4ch4d03]

If alternator is not hooked up correctly like this guys is saying, you need to regulate the charge going to the battery, or it will overcharge the battery and ruin most likely, i bought like 3 batteries until i decided to search and came up to this video and realized i was destroying my batteries, and another reason one of my dash lights was aways on not knowing what it was.

[@panchoveliz1098]

How was yours wired up? Did it melt any battery post? Mines is only missing that last 10 gauge wire back to the positive battery post and I believe that’s what melted the ground terminal on my battery.

[@canalm4ch4d03]

@@panchoveliz1098 was wired 1 wire before, and the alternator never stops charging as a result batteries die and the alternator voltage regulator could fail, iwas using a 8 gauge wire, and you absolutely need those 2 wires connected, to find out witch side is the dummy light just plug in the battery and the alternator charging wire, hook the dummy to the battery and just touch one of the ports on the alternator and see witch one turn on the dummy light and plug it there, and the other one is the regulator back to the battery.

[@gachafans297]

Can you tell me why when I hook my battery post up my headlights come on,and why my truck not turning over .only when i run a wire from my starter but no turn over from my ignition. But it lights up.

[@American-OutdoorsNet]

@@gachafans297 aounds like you are able to complete the circuit which is good. Confirm the obvious first beginning with the starter/solonoid.

[@likamafi6593]

Thank you Sir..been trying to find info on how to wire a Mahle alternator generator to a 5000 ford tractor..would this apply the same??

[@fourfortyroadrunner6701]

DO NOT use the wiring in this video. IT IS WRONG. USE a series warning lamp or a DIODE in the no1 lead or you will eventually fail the DIODE TRIO. Info i nthis video is WRONG

[@tomference4618]

Can you advise if I need to put a fuse in the #2 line when I insert an ammeter? Is polarity of the ammeter important? Also, I want to use an old 1950 amp gauge,..is that possible? Amps are amps right? Thank you for this teaching video!

[@fourfortyroadrunner6701]

NO2 was not normally fused. If the ammeter reads backwards, just reverse the connections. You can use any amp gauge if it has enough capacity, AKA don't use an old 30A gauge on a modern 60A alternator. The info in this video is WRONG

[@tomference4618]

​@@fourfortyroadrunner6701thank you for your advice about the ammeter, and not trying to use my old '50 ammeter. Can you advise how to connect the warning light?

[@clubhousemma7360]

very good, thanks!

[@johnzuggster375]

Much Appreciated!

[@clintmcalister7834]

Exactly what I needed. Thanks

[@American-OutdoorsNet]

Glad to be of help. Thanks for watchng.

[@garyalford9394]

Go thru the junk yards and search for one that hasn't been messed with, thats what I did with a 69 2500 I redid years ago.

[@dongeorge4037]

Ok, 10 gauge output, but your replacement grounding wire seems to be 10X larger. Why?

[@johngillon6969]

he said in the video you can never have too much grounding i believe.

[@American-OutdoorsNet]

The ground bolt behind the alternator is designed for a large connector and ground cable. Yes, when using a ground cable for an alternative/backup ground, more is better.

[@Rambow145]

Thank you

[@fourfortyroadrunner6701]

Info in this video is WRONG

[@lenturtle7954]

Well done

[@American-OutdoorsNet]

Thanks.

[@abcardenas35]

Can you just run?The ten gauge were directly to your battery and don't need to use pin number one and 2

[@fourfortyroadrunner6701]

Maybe if you use a "one wire" regulator, otherwise no. The info in this video is WRONG

[@carlosprimero1383]

Awesome video! Thank you!

[@American-OutdoorsNet]

Glad I could help. Thanks for watching.

[@leewilkins8341]

Thanks

[@American-OutdoorsNet]

Thanks for tuning in.

[@RWilde-m1v]

Thanks!

[@godsownlunatics9650]

i have an alternator, the harness has3 wires protruding from its connector, 1 of the 3 is bigger then or thicker than the other wires. i m attempting to create a generator for another idea of an inexpensive e-v conversion i intend to use the alternator as the genset that will power the 120vac or 240vac electric motor using an inverter. my ideas are plausible well thought out ideas nobody is willing to help pay for anymore creative ideas coming from me. hard lesson to realize i live

[@godsownlunatics9650]

I can hook up a 12volt car battery charger to a 4000watt inverter and still have enough power to run a hair dryer for example as long as the genset is creating perpetual power it can and will run for as long as it is plugged in

[@godsownlunatics9650]

meaning why would anyone use 14 car batteries when 2 regular car batteries will do the same job

[@godsownlunatics9650]

women think i think i m a baby men think i think i m an idiot and babies love me cuz i'll blaze weed in the childrens section at walmart. i m so sick of humanity gouging m,e for creationalist ideas

[@gentlegiants1974]

I'm looking to install this type of alternator on a IH Farmall 826 diesel tractor. It has a Delcotron externally regulated alternator and the old wiring harness is totally shot, grease encrusted, dried out, frayed, cracked, bare, broken, turning green, and none of the lights or gauges worked anyway. Hoping to simplify this absolute rats nest of brittle broken crap and get rid of it. All I need to run is the starter.

[@heyjohnson5535]

I'm here trying to wire my IH 1466. The old one took a poop or my buddy cut the wrong wires idk so now I got to rewire it cause my baler won't cut the twine without it charging and I got a cluster of wires to. I think I'm gonna go to part store and get a new harness can tell them the alternator and just get the cheepest option. Had no less then 8 people say they'd do this properly for me so I bought wire and shrink wrap and no one ever came so I'm left scratching my head wishing I went to mechanic school instead of welding cause at the moment it isn't fixing my tractor lol.

[@humberger2011]

👏🏿👏🏿👏🏿👏🏿👏🏿👏🏿👏🏿

[@brentalexander3459]

My charge light in Oldsmobile will not go out even when key is out stays on till I unhook battery

[@Glens1965]

I believe you have a short in the voltage regulator. If its a reman take her back. Good Luck.

[@tomference4618]

Great effort,..a little long getting to what everyone wants to hear though.

[@fourfortyroadrunner6701]

Info in this video is WRONG

[@vincenzoschettini5031]

🌹 'Promosm'