1993 4.0l factory a/c non op.

[Littlejon]

I have 12v through pressure switch to relay. Only one pressure switch at accumulator. I have no power to clutch. I've supplied power and ground to clutch and clutch works. I load tested the wire to clutch , the wire from pressure switch, and the 12v supply at the relay. I jumped 12v relay supply to clutch and clutch works, I'm down to thinking its the WOT portion of the circuit I did try a new relay no change, any thoughts or suggestions would be greatly appreciated.

 

[RonD]

Welcome to TRS

1994 wiring below, will be same as 1993

WOT relay is a 5 pin relay, when relay is off, inactive, the 12volts from pressure switch(s) would pass thru this relay to the AC Clutch, turning it on
Computer activates this relay when throttle sensor shows WOT(wide open throttle) this cuts power to AC Clutch to give engine less drag for passing or ?? the reason for WOT
So this relay is not used much, unless you are 18

And you must use a 5 pin relay in this application, 4 pin wouldn't work, no AC clutch power

This is the pin layout for standard automotive 5 pin relay: http://www.gtsparkplugs.com/images/mini-automotive-relay-wiring-840x.jpg

wiring diagram uses same numbering

So if you test slot 30 or 87A on relay's base, key on, one should show 12volts, if not then issue with wiring at pressure switch
If you put a jumper between 87A and 30 then AC Clutch should come on
All the WOT relay is, is a jumper wire that can be removed by the computer when needed

Ford could have wired 30 or 87A to the pressure switch, doesn't matter, so test both for 12v, AC switch on

 

[Littlejon]

Thank you I will use this info and continue my troubleshooting.

 

[Cornexav]

I have 12v through pressure switch to relay. Only one pressure switch at accumulator. I have no power to clutch. I've supplied power and ground to clutch and clutch works. I load tested the wire to clutch , the wire from pressure switch, and the 12v supply at the relay. I jumped 12v relay supply to clutch and clutch works, I'm down to thinking its the WOT portion of the circuit I did try a new relay no change, any thoughts or suggestions would be greatly appreciated.

So this is exactly how mine is, jumping the compressor shows that it's good. I tried to pull a vacuum and found out it wouldn't even move the gauges. Borrowing a sniffer I found the bottom of my compressor reeks of refrigerant. Not sure what that exactly means except that I for sure need a new compressor.