Floor Vent Won't Turn Off

Hey guys,

I tried searching here/Google and didn't find exactly what I was looking for. Could've just not seen it or used the right search words.

Anyhow, my passengers side floor vent is always on. When I use the bent switcher, the vents all swap as normal, EXCEPT that one floor vent. Wouldn't bother me except that it makes a good bit of extra noise, and I've been trying to fix the AC motor noise too, so I'm very sensitive to noise from the AC. Any suggestions why this one vent might be stuck?

 

The vent works off of one mode servo. either it shifts or it doesn't.

 

Hard to tell from the diagram; would I just remove the radio and HVAC controls to get to it? Also, it seems to be temperature dependent, as after we drove it and left it in the sun for a few hours it worked again.

 

It is a lot harder than than that to get to the actual flapper. I only wanted to show you that the mode control servo is all that controls where the heat / air goes.

Air inlet servo controls recirc or fresh air.
Mode control servo controls where the air comes out.
Air mix control controls the mixing of hot and cold air to set the temperature.