TunedPort350

I have an 88 GTA with the U52 digital dash and the C67 electronic air conditioning system. My problem is that the ECM is intermittently not seeing the AC Request signal from the control panel. When that happens the AC compressor will not turn on. I have triple checked the pressure switches and refrigerant level and they are both ok.

I know with the manual (slider) HVAC controls, if the pressure switches complete the circuit to the compressor, the AC request signal is sent to the ECM as an input to tell it that the AC is on.

I think there is more to it than that for the digital setups, if I am not mistaken, on these C67 setups the ECM receives the AC request signal and enables a relay which turns the compressor as long as the series circuit of the two pressure switches are closed. Or do they work just like the manual controls and I have a bad push button/wire connection or something like that?

I have found many different wiring diagrams, but they are all for the manual (slider control) panels. Does anyone have any experience with and/or a wiring diagram for the push button type of controls?

Thanks

stezhead54

I could also use the wiring diagram for the ac switch. Mine turns the fan on, and blows to the wind shield, and that's it. If anyone has this it would be great