Dakota 4WD V6-239 3.9L Magnum (1996)
Compressor HVAC: Description and Operation
CIRCUIT OPERATION
When the A/C-heater control switch is moved to an A/C position or the defrost position, and the A/C high pressure and low pressure switches
close, the Powertrain Control Module (PCM) receives an A/C request signal on circuit C20. Circuit C20 connects to cavity C22 of the PCM.
After receiving the A/C request signal, the PCM supplies ground for the coil side of the A/C compressor clutch relay on circuit C13. Circuit C13
connects to cavity C1 of the PCM. Circuit A21 from the ignition switch supplies power for the coil sides of the relay Circuit C26 from fuse B in
the Power Distribution Center (PDC) supplies voltage to the contact side of the relay.
When the PCM grounds the A/C compressor clutch relay, the contacts close and connect circuits C26 and C3. Circuit C3 supplies voltage to the
A/C compressor clutch. Ground for the compressor clutch is provided on circuit Z1.
