Posts Tagged: no heat no AC car

Blend Door vs Blend Door Actuator: What’s Really Failing

How the Blend Door Controls Cabin Temperature Quick Summary The blend door is a flap in the HVAC system that controls whether the air flows through the heater core or the AC evaporator. The blend door actuator moves the door to the commanded position. When either one fails—or when calibration is lost—you lose temperature control. Proper diagnosis means testing the door itself before replacing the actuator, because a stuck or broken blend door can quickly destroy a new actuator. Article Why I Always Suspect the Blend Door When You Don’t … Read More