So when i have my car on and turn on the AC i get this HORRIBLE screeching from the alternator area...... It only does it when i turn on the AC. And when it makes the noise the battery voltage drops down and becomes slightly erratic. The alternator is the original which would make it 9 years old. Think its the culprit???
Thanks.


Chris

 

Might want to check belt tensioner and AC compressor. You can run alternator in to auto zone and they will check it for free.

 

Since it only happens when the A/C is on, as stated above check the A/C pulley... Have someone turn the A/C on and off while you can locate the noise.... It might be the tensioner pulley bearing , but that is usually heard at start up.... If you have a voltmeter, the alternator should read around 13.8 to 14.2 volts running at idle.....

 

check A/C pulley

 

IF by some chance it is your alternator, I am desperately trying to sell my brand new in box Ac Delco alternator. It has never even been installed on my car...PM me if interested then, good luck

 

I had a friend look at it and he said that it is the ac compressor locking up and causing the belt to slip... So that sucks. Thanks for the quick replies. Time for a new compressor and belt


Chris