My 1997 Landrover Discovery AC problem is that the system has been checked over and recharged (it was low, not empty) and works ice cold at idle (it's a diesel). However when you rev the engine the compressor stops spinning. It does this more or less from AC switch-on so I don't think it's any kind of thermal load thing on the compressor as it has only just started running. I thought at first it might be some kind of high-pressure switch thing but it did it when the system was half full and it does it when you just blip the throttle even before the engine has revved by any appreicable amount and presumably therefore still short of peak pressure? Meanwhile, if you press the accelerator slowly it can sometimes stay spinning well above idle. Therefore if it's not a pressure switch I'm wondering if it's a compressor clutch slipping problem? My AC recharge guy says his brother had a Focus with the same problem and he took a shim out of the clutch to put the magnets closer to the pulley (may have misunderstood that bit) and the car was fine afterwards. Any ideas? Pete Crespin