1988 Chevy Celebrity AC Electrical Problem

or fuses or pressure switches or wiring, or ECM etc, etc

The circuit needs to be systematically checked with a wiring diagram to determine what the problem is.

Thanks for the schematic. I have checked the fuses. They were both okay. Time to dig out the mulitmeter.

Multimeter. They should have spell check on this forum.

You can use a paper clip to jump out the switch plugs to determine if they are the problem.

Unfortunately, the block diagram does not show me the location of the various components. There are what appear to be two pressure switches on the high pressure line coming out of the compressor. One has voltage to it and one does not. Even if I install a jumper on the one that has voltage I do not get voltage at the other. From what I can see on the block diagram, the current travels through the low pressure switch and then through the high pressure switch to the ECM and then to ground. It also travels through the compressor clutch relay to the compressor clutch.

There are three relays near the right front fender behind the grille. Is one of those the compressor clutch relay and if so, which one?

Yes, one of them is the A/C relay but the way you verify that is with wire colors. Originally it was the one on the end toward the center of the car but it could have been moved by now.

Am I correct in assuming those two connectors on the high pressure line coming out of the compressor and going upward vertically are connected to the low and high pressure switches? Or are the pressure switches located elsewhere? I did notice later that there appeared to be a connector to the compressor itself. Some of my co-workers have stated that sometimes the high pressure switch is located right on the compressor.

You can identify the switch by which line it is in. the low pressure switch will be in the low pressure side, usually right on the accumulator. If you have a switch in the compressor, that will be the high pressure switch. Again, use the wire colors to be sure.