Diamante Sedan V6-2972cc 3.0L DOHC (1993)
A/C Signal: Description and Operation
A/C Compressor Clutch Relay
Operation
When the driver turns on the A/C system, and the engine temperature is below 238° F, a positive voltage signal is supplied to the ECM (as an
indication that the A/C system is needed) and to one side of the A/C relay coil.
The ECM determines if engine conditions are suitable for A/C operation (idle speed, ignition timing and air/fuel mixture).
If conditions are suitable for A/C operation, the ECM supplies the ground circuit for the A/C relay coil, energizing it. This allows the relay to
supply voltage to the compressor clutch.