Gm alternator wiring help

Jacobmc · Jul 10, 2014

Trying to figure out to wire my alternator up properly...I've searched and can't find much on mine..mine only has two small wires in tbe plug one is brown the other is a red with black stripe..I just need to know where these two wires would go to like a switch? Do I need to wire in a resister or a light?the motor is a 95 4.3 converted to propane

Jacobmc · Jul 10, 2014

Re: Re: Re: Gm alternator wiring help

Jacobmc said:
Trying to figure out to wire my alternator up properly...I've searched and can't find much on mine..mine only has two small wires in tbe plug one is brown the other is a red with black stripe..I just need to know where these two wires would go to like a switch? Do I need to wire in a resister or a light?the motor is a 95 4.3 converted to propane

RustyC · Jul 10, 2014

Yes you need to add a resistor or light or both to the "L" terminal wire. By 4.3 alt. is wired the same.
I went to radio shack and got a small light and a 10 ohm resistor. Mounted the light at the dash.
Wire it by putting switched ignition power to the light, out of the light to the resistor, out of the resistor to the "L" terminal.

Turn on the ignition switch and the light will come on. Cranking the engine will cause the alternator to ground the "L" terminal when if starts charging and the light will go out.
This way you know out on the trail if your alt. stops charging because the light will come on. Just like GM designed it.

Note the resistor may not be needed it the light you choose has more than 10 ohms of resistance.

This can also be done with all the wiring at the engine. Finding the switched power and putting the resistor and light at the alt. If you don't need a alt. charging indicator at the dash.
Pop the hood and see the light on =bad alt.

(http://www.pirate4x4.com/tech/billavista/Wiring/Part2/#csseries)

Jacobmc · Jul 10, 2014

Re:

Do I just run this red wire with black stripe back to the post?

RustyC · Jul 10, 2014

The "F" terminal red/black wire is not used it I remember correctly. I think I just taped mine back to harness under loom. I can check this afternoon.