94 F150 air conditioning

my a/c compressor is not getting power. i've checked and found that the switch is working. ive tried tracing the wires, but it is too difficult. my chilton's manual doesn't include anything to do with the A/C for safety and environmental reasons; they don't even include the wiring in their schematic. isn't there a pressure switch or something in the system? or does someone know where i can get a good wiring schematic? thanks in advance.

Helm has very good factory repair manuals. Here is a list for the f150.

http://www.helminc.com/helm/Result.asp?Style=&Mfg=FMC&Make=FCT&Model=F150&Year=1994&Category=&Keyword=&Module=&mscsid=PKXHW90LAA6K8H6LNMNKA0FCX1JBD866

did you check the fuse?? there is a pressure switch on the high side near the passenger side of the firewall. try unpluging the electrical connector it should have 2 contacts and jump the contacts with a piece of wire or paperclip. if the ac starts cycling you are either low on refrigerent of the pressure switch is bad. good luck!!

what do you mean by "the high side." I am an electrician, so I am not electrially unaware. but I am not sure what you mean.

thanks,

rob

high pressure, the side after the compressor and condensor the sensor is located of the passenger side of the fire wall.

yeah, i figured out what you meant, and I found the switch. thank you. and jumpering the wires works. it looks like that switch can't be replaced without losing refrigerant, is that true? it probably isn't the switch anyhow, but i was wondering.

thanks again

actually theres a 90% chance the switch isn't the problem. the problem is your refrigerent is low therefore the pressure is too low, the switch is a safety measure to prevent compressor damage. you'll have to get the system recharged. basically all jumping the switch will tell you is that all the other electrical circuits and compressor clutch are working.

There should be a valve stem behind the pressure switch. Once its unscrewed a couple of turns no refrigerant will leak.