Air Flow Control Dial
WARNING: This page is about a different car, the 1998 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.
When dial is placed in VENT position, it allows air to flow through instrument panel outlets. When dial is placed in BI-LEV position air flows through instrument panel outlets and foot outlets. With dial in HEAT position, air flows through foot outlets and some through windshield defroster outlets. With dial in HEAT DEFROST position, air flows through windshield defroster outlets and foot outlets. With dial in DEFROST position, air flows through windshield defroster outlets.