A/C Issue

My 99 xj recently started chirping like a bird. Only does it when the A/C is on, and the vehicle is warmed up. It doesn't do it much at idle, but past 1500 rpm. It does it on and off going down the highway, I'm assuming that's the compressor clutch engaging and disengaging. I am A/C stupid, so if anyone has an idea of what the issue could be (besides the obvious fact that the compressor clutch bearing could be going) I'm all ears. Only reason I'm sceptical is because it won't do it at start up, only once the engine has warmed up. I'm just wanting to trouble shoot before I run out and drop the coin on a new compressor. Thanks in advance.

Check that belt condition and tension first!

i think its the clutch