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.