When the A/C is selected to OFF, there is no noise.
Once I put on cool or recirculation and the compressor kicks on, there is a terrible screetching noise.
It goes back away once you turn the air back off.

Is this the A/C clutch going out? Is there a way to service this or lubricate it without removal, or is it something that you just replace?

 

Does your A/C actually cool while screeching? If not, the compressor is locked up and that's the belt. If it does, the problem is either the clutch or compressor. This assumes that the belt is in good shape and properly tensioned, by the way.

 

Yeah good thoughts.
I replaced the belt and it went away for about a day.
It does cool while making noise.

 

You didn't provide much background info, so this may not apply to your situation. I once overcharged the AC with so much Freon that the compressor could barely turn and the belt screeched like mad.
Yes, I was a dumb high school kid at the time and thought the system would stop taking Freon when it reached the full point. It did not.