Recirculation Mode
WARNING: This page is about a different car, the 2002 Pontiac Montana, 2002 Oldsmobile Silhouette, and 2002 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.
When the recirculation switch is pressed, a signal is sent from the HVAC control module to the recirculation actuator through the recirculation door control circuit. When the logic receives the signal, the recirculation actuator moves into the recirculation mode. This brings air from the inside the vehicle instead of fresh air from the outside. Power and ground are provided to the recirculation actuator by the ignition 3 voltage circuit and ground circuit. Recirculation is only available when the HVAC control module is in Vent, Bi-level or the Off position. The recirculation mode will stay on and the LED will illuminate until either outside air or a non-recirculation mode is selected.