A/C Compressor Problem
AC cooling moderatly on the Hwy, not at all on surface streets. Pulled Orafice tube and it was clogged, pulled compressor and it was bearly providing any compression or suction. Got another compressor, condensor, orafice tube, accumulator.....flushed hoses, then vac'd the lines at -27 hg for an hour. Refilled w/ 134A and happily switched the system on.........nothing....compressor was not turning. Replaced the cycling switch on the accumulator....nothing. Pulled wires to cycling switch and shorted them with the ol' paper clip trick....nothing. Then clipped my test light to the positive of the battery and pierced the wires to the cycling switch and WA-LA! Everything kicked in and ran great. I had low pressure at @ 30-35 and high pressure @ 200; vent temp blew down to 40 degrees.....ah, felt good.....BUT when the probe is disconnected....it all goes off again. I shorted the pressure switch wires in the back of the compressor.....and also the high pressure cut out switch......that kicked the fans in as it should....still no compressor. When I have the cyling switch shorted out to the battery it shows "AC Requested" on my AutoXray 6000.....and goes off when disconnected. What'* up here? Bad dash module? ECM? IT was working fine before I did this work with the old stuff....just not cooling well..........Did I make a mistake....What else should I look for? I've also put a test probe from the neg. term. of the battery to the hot line going into the relay and it kicks the compressor on......it would appear I'm not getting a signal to the relay to start the compressor?