Relay Question

[Dodgebob1980]

Got my a/c working today, had to replace a leaking hose. But compressor wont come on unless I squeeze the contacts together on the relay. Old relay was no good and the only one I can find is a 5 post not a 4. Extra post is in the middle, no wire to hook up there. I tried it but still wont work unless i squeeze contacts together. Is my problem the relay or should i look elsewhere. truck is 93 with getrag

[ellis93]

Is the alt charging? Reason I ask is because the computer controls the alt and compressor relay,only turns it on if the computer senses engine rotation by the crank sensor.

[Dodgebob1980]

Yes alternator charges good, cruise works good, checked continuity on switch in dash, all fuses, pressure switch all ok, been thinking of just wiring in a toggle switch to relay. But if it a simple fix id like to do it right.

[PToombs]

I'd look further into it. Check for power and ground on the activation circuit. Either the high or low pressure switch may be bad or tripped because of pressure. Or no power to it.

[ellis93]

yep....probe the wires on the switch off the side of the expansion valve.

[bmoeller]

Bad contacts in the relay holder?