Trying to troubleshoot an ac problem, compressor won't kick in when the pressure cycling switch is shorted. The service manual is somewhat vague about the location of the compressor control relay and the a/c control head connector. I have a 86gt. The diagrams show 3 relays mounted in front of the air filter. My gt only has 2. It also alludes to checking voltages at the control head connector, but doesn't show where it might be located. Sure could use help here.

I don't have AC, but going by Haynes manual it shows relays to the side of the accumulator up front under the hood, just behind the spare mounted to the firewall. It shows 2 relays.....the one closest to the accumulator is Power switching relay and next to it (furthest from accumulator) is High blower relay. hope this helps

Fixie!!! Fixie!!!

The head control unit is the switch cluster mounted in the dash. The edge connector connected on the back side is numbered alphabetically a to n. n is +12v from the fuse box. To get +12v to the compressor clutch, the head control switch has to be set for either max, norm, or b/l. This should route +12v to the g finger on the edge connector. After removing the metal top cover I could see where a peice of etch between a bank of switches had disintegrated. A quick peice of wire soldered between the 2 points gave me +12v at the g finger. Cranked up the GT, and Whala!, compressor cycles. Now I'm off to Big Lots to get R134a ( $4 a can ). Still would like to know where the compressor relay is though. Anybody ever messed with one?

[This message has been edited by flimbob (edited 06-14-2008).]

Compressor relay is on a bracket on the front left engine bay firewall, the other relay on the bracket is for the fuel pump. They're the same relay part number so are interchangeable.



JazzMan

So the coolant fan relay is located somewhere else?

That I don't know. The picture above was taken from the '86 manual. I do know that the radiator fan relay is a different shape with inline connectors than the fuel pump and compressor clutch relays. My own direct experience is with '88 models which only have two relays at that location.

JazzMan