WOT relay stuck open, need help finding out why

[blue83ranger]

My truck is an '86 ranger 4x4, formally an a4ld and now a c4. The problem is that the a/c clutch wouldn't kick on and i traced the problem to the WOT relay. Just so i could have a/c i unhooked the relay. and for a pretty long while now i get about 11-13 mpg and i tried finding any other problem and came up with nothing so i'm back to the WOT relay. So what all triggers the relay so i can do some testing on those parts. And it has quite i few new parts on it including a TPS for a different reason than this. Thanks for any help.

 

[kimcrwbr1]

Did you reset the computer when you replaced the tps. The tps is what tells the computer to turn off the a/c clutch so maybe your computer just needs to be reset. Disconnect the battery for at least 30 mins and make sure everything is plugged in when you start it. The map may also have something to do with the WOT relay but you say you changed a bunch of stuff. Maybe you could find a computer at the bone yard for cheap if you still have the same problem then you likely have two good computers. The chances that two computers have the exact same fault are next to none. Have you tried a WOT relay maybe it is faulty. Just throwing some stuff out there.

 

[kimcrwbr1]

I cant find a schematic for the 86 a/c wiring but they are all very similar. lt grn/ppl is hot to the wot relay with the a/c switch on and also tells the computer the switch is on pin 24. There are two reds to the relay one is key on hot and the other pin 54 I am guessing is the ground to the relay coil. So with the a/c turned on and the engine running you should have power to the two red wires one hot the other ground that closes the circuit to the clutch. The pressure switch is on either side of the wot relay depending on your setup blk/yel wires. I believe the defrost control also turns the a/c on to pull the moisture out of the cab but cannot confirm that without a detailed diagram of the A/C system.

 

[blue83ranger]

I thought i reset the computer but i'll do it again to make sure. The MAP sensor has been replaced with no change and the vac hose going to it has no leaks. Also i'm running the computer off my '88 2.9 which has a/c and an A4LD. But i also have 2 others that'll work but never really tried them to see if it fixed this problem. and i would have to double check but i think one of the red wires is the wire i unhooked to get the a/c to work.

 

[blue83ranger]

I reset the computer, no change. And the truck the computer came out of had no a/c problems. and it was a red wire in the WOT relay i unhooked. When it was hooked up if i would turn the a/c on and jump that wire with 12 volt the a/c would work for a while, usually until i turn the key off, then i would have to jump it again.