Blend door not moving from defrost position

DINKY1950USA

MEMBER
2011 GMC ACADIA
3.6L
4 CYL
2WD
AUTOMATIC
100,000 MILES

The air is blowing out of the defroster vents, very little on the floor. None out the A/C vents even when you have the system out of automatic and manually switch it to A/C vents. I removed the HVAC fuse for a minute and started the car, then waited 40 seconds before turning the controls on and it still is in the defrost position.

3 Replies

STEVE W.

MECHANIC
13,465 POSTS

That sounds like a bad mode door actuator. Item 5 in the image. To get to it you need to remove the insulator panel under the glove box, then the glove box itself by removing the screws that attach it to the panel. The actuator is then inside that opening on the left side. You remove the 3 screws and pull the actuator out. Put the replacement in and then connect it. Next pull the same fuse you did the first time and reset the system like you did the first time. That should initialize the actuator.
I have replaced them simply by dropping the glove box down but you need to be able to work by feel doing it that way as you can't get light in there to see.