That sounds like a bearing. When its turned off, the clutch is dissengaged so the compressor is not spinning. Only the pully / clutch is spinning. Take a look at getting a new or rebuilt pully/clutch and see if that solves your problem
Hey Rob I appreciate the links. After using an AC Gauge Set and watching YouTube AC vids, it appears my compressor is dead. Pressure is about equal on both high and low pressure sides which according to the diagnostics videos means compressor replacement. Anyway I was wondering if you had seen any info on here for replacing it? I found some discussion on clutch replacement but not whole compressor.
I have not but I have removed the AC compressor on my car and its just like pulling the alternator. Take it to an AC shop and have them pull the refrigerant out. They will store it for you. Then go home and remove the failed AC compressor and install the replacement unit. Once its in place, go back to the AC shop and have them refill your system. They will "give" you the equivalent poundage that they removed and make sure the system is charged to the proper level. They can also check for any leaks and if there are any fix them. Then you are good to go.