HVAC Blend Door Actuator Replacement
What is a blend door actuator?
In a vehicle's heating and cooling system, the blend door actuators help control the air temperature from the vents, and direct air to selected vents.
How does the blend door actuator work?
To blow heat into the cabin, the blower motor sends air through the heater core and on through the dash vents. But when heat is not desired, the blend door actuators direct that airflow away from the heater core.
There are also actuators to direct air to the dash vents, floor vents and windshield vents depending which setting is selected.
In addition to improper temperature and/or air flow output from the dash vents, you may also hear a clicking noise from behind the dashboard.
What are the symptoms related to a bad blend door actuator?
The symptoms of a bad blend door actuator include a lack of heat or air conditioning, or failure of air to blow through some or all of the vents. The actuator motors may also make a noise if they've failed, but this isn't always the case.