Quote Originally Posted by LostBenji View Post
Got an A/M sucker on mine, no issues. Might need to investigate why the squeal rather than treat the symptom.

Rosco, do you have a dual battery system or if single, are you draining it too much?

I have seen this before with too much load on the alternator thanks to stupid/dumb dual battery setups that connect both batteries to the poor alternator at same time. Also get same issue if the alternator is bad and has shorted windings or diodes.
Not saying that won't happen but usually it is because of insufficient belt tension due to a siezed tensioner so the new tensioner should have sorted that out.

95% of electronic dual battery systems (100% of the non-programmable VSR based ones) will connect both batteries within moments of engine start anyway.

The Alternator whining like a Dog with its 'nads caught in a rabbit trap and/or the Alt warning light should give the OP a heads up if it is overloaded or faulty.

Given that the OP didn't mention 'only at night with headlights on' or somesuch then the issue appears to be there no matter the Alt load,
but...
A quick listen and a check of the Alternator idle voltage with minimal load IE no lights etc and then again with main beams, spotties etc all on and A/C fan on full will help ID or rule out that as a cause