Hi guys, I have a 99 f150 with the 4.6L romeo, and it sounds almost like a rattling pulley and off and on belt sqeeks, the alternator was replaced by previous owner, and its also overcharging, could that be my culprit? any help is greatly appreciated, thank you in advance

 

Take the belt off for a short test for noise.
Over charging; have you checked with a voltmeter ?
If the battery is good, is the voltage close to 15 volts right after starting then comes down to about 14 volts in a few minutes?
Do the checks to see if the Alternator is working as it should.
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Over charging runs the system voltage too high, causes the head lights to brighten and dim with speed, causes short bulb life, cooks the electrolyte out of the battery and shortens it's life, wears Alternator brushes excessively, loads the motor more.
What do you have?
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