jfreak

Hey guys, I'm doing a custom build and need some help regarding the alternator wiring.*
I have a 3 wire alternator, part #*25888970, and the GMPP harness I bought has one orange wire going to the middle terminal on the alternator. What are the other 2 pins for? And do I need to run another wire to switched power for it to charge properly? Also I've read that it needs a 12v supply on some sites and others say 5v.... Which is it? Lol*

Thanks

(links to the kits I'm using)
Accessory drive
http://www.crateenginedepot.com/stor...7-P1735C0.aspx

Harness
http://www.crateenginedepot.com/stor...P2221C242.aspx