HPI Vorza 2/28/2011Well, open the hood and with the engine off locate the AC compressor. It has a funny looking pulley with an almost flat face and lots of complexity to it. This is the compressor clutch, and it is what you engage when you push the AC button. Now that you have found it, shine a flashlight on it and have someone start the car with the AC off. See how just the outside ring spins and the center does not. Now, have the assistant push the AC button and see if the center starts to spin as well. If yes, it will need to go to an AC certified shop for more complete diagnosis (BESIDES THERE IS A CHANCE THEY NEED TO EVACUATE THE FREEON WHICH NEEDS A SPECIALIZED MACHINE SO EITHER WAY YOU WILL END UP IN A REPAIRSHOP). If no, it means that you have a problem with the clutch itself and or the switch and relay that control it.