92 Accorc A/C question

When you turn on the A/C, does the radiator fan and the condenser fan turn on? Do you have fuel injection or a carburetor? When you turn on the A/C with the engine at idle, does the idle speed increase a bit? Is this a California car, a 49 state car or is it in an entirely different part of the world?

The connector to the compressor clutch is in the area where you work when replacing the timing belt, as is the refrigerant pressure switch. It is also possible that you have a leak in the A/C system, particularly if the mechanic had to move the compressor out of the way to get access (not sure if this is required on your car). If the refrigerant level is low, the A/C will not turn on.

Check the bi-pressure switch first. It sits right above the high pressure port, driver's side of the car close to the condenser. It is in the pipe going from the receiver dryer, over to the passenger side and back into the cabin. The pressure switch has two wires going to it, one BLU/BLK, the other BLU/YEL. Disconnect the wires to the switch and measure for continuity between the two terminals on the switch. There should be continuity (with an ohmmeter you should see several ohms at most). If you do not have contiguity, you either have a broken pressure switch or you are low on Freon.

With the pressure switch disconnected, turn on the A/C switch and turn the ventilation fan to any speed except off. Ignition should be off. Then measure for continuity between the BLU/YEL wire and body ground. There should be continuity (again, no more than several ohms on the ohmmeter). If no continuity, it could be a bad ventilation fan switch, a bad A/C switch, a bad A/C thermostat or a broken wire.

So there are no relays to check?

Thanks for the detailed diags. Will work through these this week, job permitting.