It is possible to by-pass the hi-temp sensor located on the compressor. I hesitate advising you how to do this, but my understanding (which may be inaccurate) is that the connectors located on the right side (nearer the driver-side fender) are pulled apart and one end can be connected to the larger wire that circles around the back.. It's easier to get to this from underneath. I suspect the connection will be clear once these wires are disconnected, but thisis where I'm unsure of myself. The bypass will allow you to determine whether the switch needs replacing.

Unfortunately, I think this switch is not available (from Volvo) as a separate part...yep, you need to replace the compressor!. My mechanic friend thinks it is the same switch as that found on the S80 (or is it another model? ...yikes my memory is horrible.) which is replaceable.

Sorry to be so vague, but it's for your own protection...

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John Shatzer, '97 V90 @ 115K