im a few weeks into my proud ownership of an 88 BJ74 with the 13BT, auto, and AC. The AC has worked wonderfully but shut it off this morning and came back to it about an hour later and no AC. 
P.O. Seems to have replaced the 24volt compressor with a 12volt unit running through a voltage reducer. I started there but that checks out fine. 24 volts jumpered to the clutch wire will engage the clutch, jumperingbthe pressure switch does not. Moved inside and pulled the dash switch but it checks good too. Any ideas? What to check next?
P.O. Seems to have replaced the 24volt compressor with a 12volt unit running through a voltage reducer. I started there but that checks out fine. 24 volts jumpered to the clutch wire will engage the clutch, jumperingbthe pressure switch does not. Moved inside and pulled the dash switch but it checks good too. Any ideas? What to check next?