Wiring guys need some help or diagram..Alternator related

I was talking to a guy today w/ a carbed 87 gt. He gutted the entire car wiring and all and he's trying to rewire the alternator himself to make it work. He said the alternator is not charging his battery, took it for a drive and the car eventually died since the battery wasn't charging. The alternator was tested at 2 different stores and is fine. Anyone have a wiring diagram w/ the correct gauge wire listed to rewire this thing to work. Looked to me like he had too small of a wire so that's why I'm asking about the gauge wire used.

or better yet anybody list and explain where each wire does in the factory harness. I have an extra lying around that might help him out so we could just work from that but I would need to know what all those wires do.

Thanks hissin, I'm pretty sure he messed w/ that wiring too. He approached things a little differently. He didn't use much factory stuff. He has all his lights, wipers, backup lights etc.. running off toggles.