Diagnosing high voltage
Found this on b-bodies:
step 1. unhook both small spade terminals to alternator and start car, it should not charge at all. if it does its a bad alternator.
step 2 hook up the small 12v wire to the bat spade terminal on alternator but leave the green wire off the field terminal, if it charges at all its a bad alternator.
step3 hook up all 3 wires on alternator, unplug triangle plug on voltage regulator, if it charges than the green wire from alternator to regulator is shorted to ground.