Temperature Control Knob

The temperature knob mechanically operates a cable through a cam mechanism to adjust position of temperature blend door. Temperature blend door is in plenum assembly. When temperature knob is in cool position (turned fully counterclockwise), temperature blend door stops airflow to heater core. See Figure. When knob is in warm position (turned fully clockwise), air is directed through heater core. When knob is in intermediate positions, heated air is blended with cooler incoming air to achieve desired temperature.