Recirculation Mode
When the recirculation mode is requested, whether manual or automatic, a solenoid inside the vacuum control assembly connects the recirculation actuator to the vacuum source. The HVAC control module grounds the recirculation mode valve solenoid control circuit. The recirculation actuator retracts, closing the recirculation door. This draws air from inside the vehicle instead of fresh air from the outside.The recirculation mode can be used in both automatic and manual operation. The only time recirculation is not available is when FRONT DEFROST or MIX-BLEND is selected. The recirculation LED will flash to alert the driver that recirculation mode is not available. The recirculation LED will not illuminate in automatic mode. When in automatic mode, recirculation will stay on until either the vehicle operator selects OUTSIDE AIR or the automatic system has cooled the vehicle sufficiently. The recirculation mode has a 10 minute timer. After the timer expires, the HVAC control module will command OUTSIDE AIR. Any time the recirculation button is pressed the A/C compressor clutch automatically engages.