2500 4x4 Pickup L6-359 5.9L DSL Turbo (1995)
A/C Signal: Description and Operation
OPERATION
When either the A/C or Defrost mode has been selected and the A/C low and high-pressure switches are closed, an input signal is sent to the
Powertrain Control Module (PCM). The PCM uses this input to cycle the A/C compressor through the A/C relay.
If the A/C low or high-pressure switch opens, the PCM will not receive an A/C request signal. The PCM will then remove the ground from the
A/C relay. This will deactivate the A/C compressor clutch.
NOTE: The A/C control system information applies to factory installed air conditioning units.
