Alternator seized... or something...

It's called cheap crap rebuilts. They have been this way in some measure since I was young THE FIRST DANGEROUS DEFECTIVE REBUILT alternator I ran into was about 1978

I worked parts then. Some guy had bought a replacement (isolated field) alternator for his '70's pickup. Came back in a day later and said "it's overcharging."

I knew immediately what was wrong..........one of the two field terminals WAS GROUNDED. This means he'd had a 50-50 chance "and won." He had accidently hooked the blue IGN wire to the ungrounded field, and the grounded one caused it to overcharge. IF HE HAD SWITCHED the wires, HIS HARNESS WOULD HAVE FRIED as the IGN would have been feeding a DEAD SHORT!!!