Radiator fans and a/c compressor randomly won’t work! I am stumped and have already wasted $300.

My car is a 2002 Monte Carlo and sometimes I start it my ac blows fine and my radiator fans work great. Other times I start it the ac compressor won’t engage and then I know the fans also aren’t going to kick on when it gets to temp. I am so stumped on why these would be having issues together. AC has been recharged by a shop and they said my fans were going out bc there free spin when the car turns off. I am still having the same issues after paying that shop 300$!