My a/c clutch will not come on. It is full of R134A. If i jump the low pressure switch the clutch will not kick in. I can jump the clutch straight to the battery and the clutch will kick on and the a/c will cool fine.
My buddy had the same problem that his A/C was not kicking in. So I checked all the two pressure switch (the one on the condersor and the one on the A/C steel line near the front passenger side of the car.) I put on the A/C in the car and checked that I had voltage with my test light at the plug on the compressor and there was.....BUT if the test light in NOT the same brightness as if u touched the test light straight to the battery..then u have a pressure switch that is bad. The pressure switch that was bad on my friends 95 5.0L was the one on the condenser near the passenger firewall. Also u do not need to empty the A/C system to change this switch...just unscrew it from the condenser and u will hear a little ppsstt..of freon kinda like when u unscrew the nozzle off of a propane torch.....BLa bla bla...if u need more detailed info, just reply to my reply and I will happy to go into specific deatails such as wire colors and jumpers etc...necessary to test the switchs....but I am sure most of u guys out there should be able to figure it out