I have a 91 firebird and I was just wondering. What happens when you connect the smaller wire from the engine harness to the "L" wire on the connector?

 

Kaboom ?

 

If the F (field power enable) and L (light) wires in the connector shorted & it was not plugged into the alternator - no problem. If the plug was connected to the alternator with the two shorted, it probably toasted the output transistor in the alternator that grounds the L terminal with low or high voltage or when the alternator is not rotating - the L terminal turns on the alternator light on the dash - if you have one. The F terminal (brown wire) goes to 12 volt hot in run power through the 20 ampere fan fuse.

Are there 3 wires connected to the alternator plug on your '91? (S, F, and L) If so, what are the colors of the three wires to the plug?

Tim

 

I had to put a new connector onto the altenator. From the engine there is a large diameter red wire and a brown wire. The connector has a large red one "S", a black one "F", and a brown one "L". My father decided to connect the brown one to the brown one on the connector which is "L". Everything seems to be working normal so far.

 

Maybe the connector is marked incorrectly. The order of the four pins in the plug, starting with the large pin is S,F,P,L. The red wire goes to S pin, and the brown wire goes to the next pin over, the F pin, while the outer two P and L pins are not used. Is this how the wires are connected to the pins at the alternator?


Tim

 

The plug has from left to right S F L P. We hooked the red wire from the harness to the S terminal and the brown wire from the harness to the L terminal and left the black wire from the plug connected to nothing since there was no black wire comming from the engine harness. So far everything seems to work normally.