I'm having a problem with my ac not cooling. I have checked the coolant and the level is where it should be. It sounds like the ac is kicking on but it doesn't cool. I have heat. When the heating/cooling unit is turned on it'll kick in and the car goes into a fast idle ( i haven't noticed how high exactly but not crazy), then in a few seconds it shuts off and idles down, a few seconds later its back on and idling high, it's constantly repeating this process. I have a 2000 Sable 24v DOHC 3L. I appreciate any help in this regard. Thank You

 

When you say you checked the "coolant" I assume you meant the refrigerant. If the charge is up where it should be you should check the pressure cycling switch next to varify it is keeping the compressor clutch engaged until the system reaches proper operating pressure.