The 88 GTA I recently picked up had its original serpentine system replaced with a v-belt system and the alternator wiring was hacked in the following way:

Both the red and tan/white went to the alternator with the dark brown (or is it black) wire left unattached. I have replaced the v-belt system with a serpentine system and picked up a three wire pigtail for the alternator. The new pigtail has a red, black, and light brown wire. I've looked at a couple of wiring diagrams for this car non of which agree with each other so I'm stumped as to which wires to hook up together. Obviously the reds go together but, should I tie them together at the post on the back of the alternator or simply splice them together? I'm really not sure how to tie the other wires together and would appreciate any help. Finally, if you think something looks wrong as far which color wires are there let me know as I can't be certain that a previoius owner didn't change the routing.
Thanks,
Tony