Verified answer

low freon would be my first guess.

The secong reason could be what I had to do to my wrangler clutch a few weeks ago. The clutch would not engage or stay engaged due to wear on the clutch on the compressor. I removed a bushing and now it is chillin agian.

I wonder how many people replace compressors when it could be normal wear and just need to be gapped correctly.

sounds more like the fan clutch is worn out not pulling enough air through the condenser in front of the radiator have it checked or with the engine off the fan should have some resistance on it if you turn it by hand if not and it spins freely then have it replaced this will cause to much head pressure to build up and not let the a/c blow cold if you are saying that 40 mph or above the air blows cold this is your problem.

either the freon level is getting really low on it or the compressor is not staying kicked in which either way could still be the freon low in it, have a shop check it and see if it needs a can added to it ,and also have the check the amount of pressure its running at idle speed,good luck.