1987 Chevy Truck altenator

Other Category problem
1987 Chevy Truck V8 Four Wheel Drive Manual n/a miles

my alternator has three wires one for the batt.
and the pigtail one white and one red I know where the white one goes but not the red wire so it will not charge the batt. Dose it conect to the heavy red wire that leads back to the Batt. Or does it go somewhere else?