I have a '95 850 Turbo with about 108K on it, and the AC Compressor will not come on. I just replaced the heater core (the system was blowing coolant smelling steam out the vents) and now I have clean, hot air - but no AC. I checked the computer, and I had a code "4-1-4", which, according to Haynes is a "Driver's side interior temperature sensor inlet fan seized". I removed the sensor and after a good cleaning (it was filthy) I reinstalled it and it works fine - no more 4-1-4, but still no AC. I checked the low pressure switch on the AC line (right near the firewall) with my meter, and it is open, which would indicate low freon, right? So, I hooked up some R134a, and jummpered the switch and the compressor came on, the AC blew cold, but it sucked up little freon. I disconnected the can, and kept the system running a little longer - still is blowing very cold, but the switch pressure switch still measures open. If the AC is blowing cold, and it does not want draw any freon, it should be charged, no? This leads me to believe the switch is bad, is this a correct assumption? How can I test the switch? Do they go bad often?

Thanx!

SteveL