Recirculation Operation

The recirculation actuator controls the amount of fresh air brought into the vehicle through the HVAC system. The recirculation actuator has only 2 voltage inputs. The first is ground which sends the actuator to the recirculation position. The second is 12 volts which sends the actuator to the outside air position. The recirculation actuator is controlled by the HVAC control assembly and the powertrain control module. The PCM will ground the recirculation actuator control circuit when the A/C high pressure is above 2413 kPa (350 psi). Once A/C system pressure falls below 1724 kPa (250 psi) the PCM will remove the ground and allow the HVAC control assembly to control the recirculation actuator.

When the recirculation switch is pressed and the system is in outside air position a timer relay, internal to the HVAC control assembly, is energized. This relay has a time of 8-12 minutes to supply a ground to the recirculation actuator control circuit. Also when A/C is on and air temperature switch is in the MAX position recirculation is forced. Outside air is forced in the Defrost or Defog mode positions as this will keep the windows from fogging.