A.C. compressor clutch bearing

[blaze17]

The noise started about a week ago. Just identified it. When the a.c. compressor clutch is engaged it's fine. But when the compressor cycles off or the a.c. is turned off and the clutch freewheels it sounds like the bearing is trying to seize. If the bearing fully seizes will it simply act like the clutch is engaged and turn the Compressor? If so would it be bad to let it turn all the time?

 

[alumarine]

It could be the idler pulley bearing.

 

[nissanh]

If the bearing freezes, it will destroy the drive belt, and no, it will not turn the compressor (if AC is off).
You can replace the bearing in the compressor without removing the compressor off the engine or recharging the gas.
Make sure to buy OEM NSK bearing. About $35 on ebay. I used a Chinese bearing into my car AC compressor ($17). It is now 7000 miles and the bearing is shot. Still makes no noise but it has a side-way play about 1-2 mm.

http://www.toyota-4runner.org/3rd-g...ressor-bearing-idler-bearing-replacement.html