My ac compressor is grinding when I try and use it. While the truck is ideling its fine but as soon as I start driving it makes a funny grinding sound. It has also burt up a few belts last year when it started doing this. I have a 5 month old and it was 95 degrees today. I also looked at some youtube videos that showed me that someone had this same problem but they had a different compressor. I'm hoping I can fix mine as well SOMEONE PLEASE HELP

 

Is it making this noise only when you have the ac on? You will have to pin point where the noise is coming from if it's not the compressor, even with the ac off it could still be the compressor.

 

Even when the AC is off the compressor clutch will engage with the defrost on. I would pull all belts and spin all tensioner pulleys and idler pulleys then rotate the ac pump by hand then the ac pump Pulley.

 

You didn't mention the vehicle. You post as I read with belts off everything rotates freely? In defrost mode, the ac clutch is engaged? Based on your post's I'd say you need to replace the compressor. In defrost mode could be the old bi-level. That had ac/outside air for not defrost but "defrost" in the summer weather.

 

"Even when the AC is off the compressor clutch will engage with the defrost on. I would pull all belts and spin all tensioner pulleys and idler pulleys then rotate the ac pump by hand then the ac pump Pulley."


Kevinpk.
I was just responding to the post. and on most vehicles the AC will turn on with the defrost on. it dryes the air so the windshield will not fog.