My compressor is cutting out at speed, it will freeze you out of the car at idle up to 4500 rpm, as soon as I drive the car for a few miles it cuts out and will not come back in till the car is shut off and sits for a while, this would lead me to a pressure switch failing which I can not find! while the compressor is out the relay is energized, but the clutch doesn't engage possible failing temp sensor on the compressor? I don't have a wiring diagram so I'm not sure if this is a computer issue or the sequence of high low or temp. my low side pressure is 30 lbs at 4000 rpm. any help would be great. THX Chris

Get the car warm so the fault occurs then bridge the compessor relay connections (relay in engine compartment fuse box) with a bit wire (check there is batt voltage there), see if the compressor "clicks in". If it does you prob have a gas/sensor/control fault. If it does not, check that you are getting a full 12 volts at the compressor and a good earth. If you are then the gap between the turntable and belt pulley on the compessor electromagnetic clutch could be at fault. This gap can be adjusted by shimms but involves removal and partial stripping of the air con compressor.

I have jumped the relay but the clutch doesn't engage. is the compressor temp switch the only component between the relay and clutch coil?

Have not got your exact car details but im sure that the only sensor/switch that is between the relay and compressor is the pressure cut off switch and this is integrated/part of the compressor.

I had a problem ('04 V70) where the a/c would run until the evaporator iced up and no cold air could get out. It was worst when the outside air temps were around 90F and the humidity was high. It would recover overnight (presumably because the ice melted) and would work the next day. However, the longer the ac was on (the longer the trip) the worse it would get. Dealer replaced the evaporator and charge system under warranty. The evaporator temp sensor (30665118-3) was also replaced. It has been fine since.