1994 F-150 AC Compressor not working

[saurd]

I have a 1994 Ford F-150 4x4 step side. The AC does not work. Figured it needed a charge of R-134, but in order to add you need to get the compressor to run. First thought was to jump the wires at the sensor located on the dryer, which I had been told was the right place to do so. Still no compressor. I then hotwired the compressor right to the battery and the clutch engaged as it should. I then started the truck and engaged the compressor to see if the R-134 did indeed need to be charged, the air produced by the system was cold, so I have concluded I do not need to add any R-134.

The major question at this point is why the compressor won’t engage as it should. I check the fuse and there is power at the fuse when the compressor should be on. I check this with a meter. My question is where to look next? Do these dash switches go bad? If so how to I verify? Is the fuse under the dash before or after the switch in the circuit? If before, the switch is probably working. If not it could be the switch. A wiring diagram would be helpful, any ideas where to get one that would include the AC system? Haynes doesn’t as far as I can see.

In general any ideas on where to go next?

Thanks,
saurd

[saurd]

Good Day. What would be the best wiring diagram to get for this viechle there are alot of them offered on line. Which one has been the best?

Thanks,
Saurd

[toyoglenn]

i would check the ground wire just because you have power at fuse doesent mean the circuit hasa good ground with out good ground will not work

[Davescort97]

The electrical system for the AC starts out with the fuse then it goes to the AC switch, then it goes to the low pressure switch and then it goes to relay module and then it goes to the clutch on the AC.

It could be the switch or the relay module. The computer switches the AC relay on when it is supposed to be running. You have bypassed the switch and the computer and the relay. So it could be any one of these three things.

The fuses to be looking at are the 10 amp HEGO, 30 amp blower fuse and the AC fuse. On an Escort wagon the clutch fuse is the rear wiper motor fuse. So, it is hard telling exactly which fuse could be burned out on your vehicle. I would pull and check all of them. The clutch fuse could be in an unlikely place.