Voltage regulator/alternator question (lots of questions)

[shifty]

Started working on the LS1 swap again this weekend. I was getting the wiring cleaned up and further pruning out the engine bay. Ran into some questions, and the Haynes manual ain't helpin so much.

So, I'm using the stock 1-wire alternator from a 2001 Trans Am WS6. I do not know much about alternators - is a 1-wire alternator internally regulated on the voltage? If "yes", this answers a lot of other questions.

I have two lines going into the truck: A fat ass red wire (10g?) and a skinny brown wire. The brown wire goes to the voltage gauge and fuseblock (hot-in-run-or-start). Does anyone know what that fat ass red wire is for? It is in the bottom corner of the fuse block closest to the inner fender, if that helps. I speculate this could be for the lights ... or it could be supplying power to the fuseblock - which is it? What is its purpose?

At this point, I guess I just need to know if both the red and brown wires going to the bulkhead need to have voltage regulated or if they can be straight hot from the battery (with fusible link, I suppose?). Once I get thta figured out, it eliminates most of my wiring woes.

This is just for my reference:

I removed the voltage regulator with four wires coming out of it - red, white, dark blue and brown.
Red goes to the alternator and battery (via bulkhead on pass. side).
Blue and white had a molded connector to tap onto the alternator.
Brown goes to the bulkhead at the firewall, to voltage gauge and fuseblock (hot-in-run-or-start).

If I don't write it down, my memory would surely forget.