VENT Mode
WARNING: This page is about a different car, the 2002 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
When the driver selects the VENT mode, air is delivered through the instrument panel outlets and a small amount is delivered to the floor. Vacuum is applied to the mode actuator through the Brown vacuum line, and to the defrost actuator through the Red vacuum line. The mode actuator will retract, opening the vent door. The defroster actuator will retract, closing the defroster door and open the heater door through mechanical linkage.