wires on the back of the alternator?
 

alright on the back of a VG alternator there should be 2 wires, a thick white one and a skinny tanish with a red stripe one.

what wire is the indicator light and what wire is the one that recives the signal to charge?

The bigger one (white) would obviously be the one carrying the juice back to the battery. That leaves one left. :D

ther should be 2 white wires.. both flow current... the 20 guage "little tarnash 1" is light/guage