I just put a new rectifier (Yes it was rated at the same amps as the old one) in my powermaster alternator that only had 5k miles on it. The original rectifier was blown due to a battery short.

All systems are go, however there is a high pitched whine coming from the alternator that was not there before. Before the rectifier change, it actually did make this same noise although less apparent at low RPMs. Now it does the opposite; the noise becomes prominent at high RPMs but goes silent below about 2k. It sounds like there is a mini supercharger under the hood.

I actually don't mind the noise. The charging system is 100% functional, there is no awful clacking or grinding sound and there is no sight or smell of smoke, but I am concerned something might be amiss here. Thoughts?

 

both of my powermasters whine like a supercharger

 

I'd just keep an eye on it to make sure it's not a bearing or bushing about to fail. If all is well and the noise doesn't bother you, drive on!