Floor Mode
WARNING: This page is about a different car, the 2002 Buick Regal and 2002 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
When the driver selects the FLOOR mode, air is delivered through the floor outlets with some toward the windshield and side vents. The HVAC control module grounds both the lower mode valve solenoid control and the mix-blend mode valve solenoid control circuit. When the solenoids are grounded, vacuum is applied to the mode actuator through the Blue vacuum line, and to the defrost actuator through the Red vacuum line. The mode actuator will retract, closing the Vent Door. The defroster actuator will retract, closing the Defroster Door and open the Heater Door through mechanical linkage.