So my mom's 06 has an interesting issue. The fan is stuck on the recirculate setting. When I hit the button to change to outside air, I hear a loud knock from the passenger dash. Sounds like someone is banging it with a hammer 4 or 5 times then stops. It also does this upon start up, since it always defaults back to vented air. Need to tap the recirc button each time the car is started to stop the noise.

I assume that whatever mechanism in there is responsible for re-directing the air is shot, stuck, etc. Hell, maybe somehow a cat got lodged in there and is stopping the vent. (maybe not...car still smells normal) Anyone know how to access it? Next time I have a chance I'm going to get under the glovebox where the cabin filter is, but not sure if it's something to access from there or if the whole dash needs to be ripped open. If anyone has experience in this area please let me know!

 

there is a motor of some sort behind the glove box, may be something in there gone bad or clogged.

 

sound like the recirculation bled door actuator is bad. or the door broke free from it easy fix

 

Got any details by chance? I assume the fix is easy, just not sure how best to reach it.