My ac does not work at idle.

I had the same problem with my nissan, make sure to check for leaks using dye and also check the amount of frion being put into the system. If its low that will cause the warm air at idle due to the ac compressor switch not detecting enough pressure from the system. Otherwise, be prepared to buy another compressor.

If it works better,or cycles on and off it could be OVER filled cutting out due to high head pressure.Have your systems freon removed and refilled so the amount of freon can be checked. TOO much is just as bad as not enough.