Temperature Control Knob
WARNING: This page is about a different car, the 2001 Saab 9-3 and 2000 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
Temperature control knob regulates distributed air temperature by controlling air-mixing damper. See Fig 1 . Air-mixing damper directs a certain amount of airflow through heater core. When full cold position is selected air-mixing damper prevents air from reaching heater core.