Hey guys so I'm finishing up my swap and a little stumped with the wiring for the alternator. I'm using an ls1 alternator and have one wire (big red) going to battery and the small going to the pcm. Now off the vehicle c100 fire wall harness, I have a brown wire with a pigtail at the end, has a 1 inch red wire on one pin of the pigtail (other pin is brown wire).

from what I researched I'm supposed to hook the brown wire off the c100 to 12v ign off fan fuse, Is this correct?

is this brown wire supposed to be just for the gauge or does it work with the stock 3rd gen pcm to control when the alternator charges?
if this brown is just for the gauge can I run this straight to the battery?