Temperature Control Knob
WARNING: This page is about a different car, the 1998 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
Temperature control knob controls a blend door potentiometer which controls an electronic temperature blend door motor. Temperature blend door motor provides a variable number of temperature blend door positions. When temperature control knob is in COOL position, temperature blend door shuts off airflow to heater core. When knob is in WARM position, air is directed through heater core. When knob is in intermediate positions, heated air is blended with cooler incoming air to achieve desired temperature.