It has been a while since I've had a problem with my car, an 89 740Turbo, which been converted to R134. I've done everything to my car, except AC work. I had the system recharged in September 08. Used it in early February during a strange heat spell. Went to use it again next in early April, and no cold air, compressor doesn't come on. Checked voltage up to the low pressure switch, which was OK. Disconnected the 2 wire plug to the switch, jumpered it, compressor does still not come on. What next? Does this sound like an electrical connection problem? By the way, I do have the Volvo Electrical Fault tracing Green Book. Thanks in advance for any clues and/or tips.