I have 96 3800 SC and purchased a 99 Chevy Alternator with four leads. The pinout only accounts for three. What three I am not sure. Can anyone help? Just not sure how to go about this.

Thanks

Basically the red one from the plug goes to the Fiero's charge indicator light through the C500 connector this can be done by going through the PCM to give it control or bypassing the PCM so it does not have control I usually go with out PCM control.
The grey wire will be connected to + 12 volts ignition and the orange to + 12 volts battery for this the cig lighter will work but I wire it to the orange wire from the connector below the C500 that has battery power applied to it. The fourth pin is not used and on Grand Prix's the grey wire is not used. Dan

I tried using a 2003 bonneville 4 wire alt with an early year pcm. No matter what I did, the alt would always over charge or the volt light would stay on. I bought a GtP 3 wire to replace it, rewired, and everything works great now. not sure if it was a wiring issue or a bad alt but it drove me crazy for about a week.

Just looking for some clarification on this wiring. There are four wires, despite the colors, they are labeled P-L-I-S. What goes where?

I dont want to blow something up!!!

See cave... CS alt

P-- Not use in most OBD1 cars
Depend on how alt is wired... Measure ARPM (see cave, watt story) and OBD2 PCM can can read and give MIL errors... Alt slipping, etc.

Note: Some alt's look like a CS but uses dif regulator and needs PCM to work. PCM can shut off the alt. IE It doesn't work in most Fiero conversion.

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