I have a 78 300D, the battery started to lose charge after a drive. I assumed either the regulator or alternator. Took the old regulator out, and it was toast. Replaced it with a new one and all is well...

Immediately after installing a new regulator when slowing down to a stop, the alternator will make a screech and stop at idle. Pulling away from a stop it screeched even louder, then went out. That only has happened once so far. Just changed out the regulator this morning.

Any idea why the sudden screeching noise? It's never made this noise before the regulator swap.