Air Distribution Control Knob
WARNING: This page is about a different car, the 1996 Saab 900 and 1995 Saab 900. However, it is still accessible from the selected car via links, so may be relevant.
Air is directed by air distribution damper to defroster, panel or floor vents. Knob on control panel can be set between the 3 main settings. Air is then divided between defroster and floor, or between panel and floor. See Figure.