Alternator question

[Bob from Northport]

A customer has supplied us with his used 12v alternator, and wants his truck converted to 12v. It is a older GM alternator. I had it checked, and it is good. Can anyone advise the wire connections using standard wiring harness.? We have to install complete new wiring, lights, ect.

Also, customer advised that the original starter(6v) was fine with 12 volt system. This is the first conversion for us, but I believe that the windings in the starter have to be 12v. Correct??

Thanks!!

[Mike V. Florida]

Originally Posted by Bob from Northport

A customer has supplied us with his used 12v alternator, and wants his truck converted to 12v. It is a older GM alternator. I had it checked, and it is good. Can anyone advise the wire connections using standard wiring harness.? We have to install complete new wiring, lights, ect.

Also, customer advised that the original starter(6v) was fine with 12 volt system. This is the first conversion for us, but I believe that the windings in the starter have to be 12v. Correct??

Thanks!!

First, used from where? Has the alt been converted to singe wire?
Yes the 6v starter will work on the 12v car.

[SkipShift]

I found details for converting to 12v in vol. II

[Willie Krash]

Battery to Battery.
#1 or R to idiot light or small axial diode tied to key (on/run)
#2 or F back to the battery (battery sensed) or to the Battery terminal on the Alternator (machined sensed).
Do not put #1 to key (on) as you will not be able to turn the truck off w/o removing the alt plug.

If it's a 10DN you'll need a VR. I'd use one for a 69 Dodge anything.

[ford3]

i would suggest you advise him to get an internally regulated altenator, that way he can eliminate the external regulator for a much cleaner under hood look, they are called 3 wire alt, and none of the wires go to an external source except the wire going to the batt and one to the idiot lite

[Tom Endy]

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Bob:

A 6-volt starter will work just fine on a 12-volt powered system. The only drawback is that the initial torque applied to the Bendix is somewhat severe and it will limit the service life of the Bendix. It is possible to replace the field coils of a 6-volt starter with 12-volt field coils and make it a 12-volt starter. Most Model A suppliers carry the coils. However, I would not go to the trouble. You can also replace the original Bendix with a replacement modern device used on Ford tractors. They seem to hold up better. Most Model A suppliers carry them.

Tom Endy

[tbirdtbird]

GM one-wire is the slickest cleanest way to go

[Growley bear]

My experience with the twelve volt Model A is that the starter as well as the bendix seem to last a long time. The engine just rolls over at a higher rate and the starter as a rule isn't/shouldn't used long enough to get warm. 12 volt systems are more forgiving than 6 volt systems. A 12 volt system moves less amperage than a 6 volt system. Less volts-more amps-larger wire-better connections. I run a 35A generator from an 8BA Ford on my Model A only because I have sealed beam headlamps Which take the Model A generator from a 15A + to 15A - on the meter which is hard on the Model A generator.

Chet

[ford3]

tbirdtbird, the gm one wire has several known problems, one is you may have to wind the engine up to about 1000 rpm before it will entergize, the othe problem some times when you turn the engine ff the alt electric supply will not de entergize and stay hot, it will run your battery down over nite, ive had both of those problems happen, i now only run the 3 wire alt and i no longer have those problems

[tbirdtbird]

i've heard of this but i have them on several of my vintage cars and have never had this happen. you do have to rev the motor a bit to self-energize but not as much as 1000 in my cars; you are gonna drive it and it is gonna hit 1000 anyway....

[jrelliott]

I have the information you are requesting about the modifications to the GM alternator for both single wire and 3-wire. Send me an email and will send you the information and a diagram of how to hook up the 3-wire. [email protected] Ford3 is correct about a single wire alternator running the battery down after a while. I put the fuse mod on the starter and pulled it if the vehicle was to sit for a while.

[tbirdtbird]

jr why not post it for for the benefit of all?

[Mike V. Florida]

Converting a 3 wire to a one wire

[machine girl]

we would not take a 3 wire and try to make it a one wire no internal regulator ?

[Willie Krash]

Originally Posted by ford3

tbirdtbird, the gm one wire has several known problems, one is you may have to wind the engine up to about 1000 rpm before it will entergize, the othe problem some times when you turn the engine ff the alt electric supply will not de entergize and stay hot, it will run your battery down over nite, ive had both of those problems happen, i now only run the 3 wire alt and i no longer have those problems

Use an AC fired VR and it will turn on at idle.

[tbirdtbird]

or brake light!!!!

[Mike V. Florida]

Originally Posted by Willie Krash

Use an AC fired VR and it will turn on at idle.

http://store.alternatorparts.com/partnod10se61.aspx