Horrible screeching noise after replacing alternator

You had to open it to get the belt off so open and close it a few times and put some pressure on it when you close it. Tester is probably correct, a new belt and tensioner might be in order. Not sure if it is left hand threads gettin the pulley of but could be. Shop?

If you look at the video, most of the slack is between the tensioner pulley and the compressor pulley.

When the compressor turns on, the belts slips on the compressor pulley because it takes horsepower to turn that compressor pulley.

Especially if the belt is worn.


If it were me, I would change the belt, tensioner and idler pulley.


You don’t have the belt routed correctly around the water pump, this makes the belt seem too long and not enough contact on the compressor pulley.



Well that would do it.

This was it, this fixed the issue, I had put the belt back on wrong :frowning:
Thank you so very much everyone for taking the time out to help me with this, going forward ill definitely take pics before starting other projects. Thank you so much :slight_smile:


Good for you for sticking with it and garnering a diy’er repair. If any of those pulleys was turning backwards while the belt was wrongly configured, and problem later develops, consider that as a possible culprit. As far as I can tell both the water pump and alternator pulley was turning in proper direction. Taking photo before disassembly is good idea. I usually just sketch it out on the shop notebook.