System Controls: Floor
WARNING: This page is about a different car, the 1994 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.
Outside air is drawn into system, blown past evaporator core and through heater core. Vacuum closes windshield defroster door and opens heater air damper door. With knob in FLOOR position, air is also fed to demisters.