Air Door Position Sensor / Switch: Description and Operation

BLEND SWITCH
The rotary Blend Switch has multiple detents to control the full range of temperature that the system can produce in any mode. Provided that the Blower Switch is an any of the four ON positions, rotating the Blend Switch will result in the A/C - Heater Control sending a signal to the BCM to signal the actuator to move the blend door. A potentiometer, inside the Blend Door Actuator, and feedback circuits provide the BCM with door position information.