Volvo Repair: 94 850 A/C, compressor clutch, pressure switch

Question
My  94 850 volvo non turbo A/C does not work. The clutch on the compressor does not engage. I checked the high pressure switch with an ohm meter and determined that the switch was "open" thus indicating low freon. I bypassed the high pressure switch but this did not engage the compressor clutch. How do I determine if the clutch is bad. Or what other steps can I take to help isolate the problem?


Answer
James, check for power at the connector of the pressure switch.  I had that problem today and it turned out to be the relay.  You may also have a problem in the control head.  Check freon levels.  The evaporator is a common occurance on the 850's.  Its cheaper in the long run to change the compressor.  The clutch itself is expensive.  Roger