A/C Signal: Description and Operation

^ Once Air Conditioning has been selected, the PCM receives the A/C request signal from the evaporator switch. The input indicates that the evaporator temperature is in the proper range for A/C application. The PCM uses this input to cycle the A/C compressor clutch through the A/C relay.

^ If the A/C low pressure switch opens indicating a low refrigerant level, the PCM will not receive an A/C select signal. The PCM will then remove the ground from the A/C relay. This will deactivate the A/C compressor clutch.

^ If the evaporator switch opens, indicating that the evaporator is not in the proper temperature range, the PCM will not receive the A/C request signal. The PCM will then remove the ground from the A/C relay, deactivating the A/C compressor clutch.