I have a 07 Tahoe that i am having a problem when i change vents from defroster to face vents will often not change over,but will sometimes. I live in small town and dealer says the only thig they know to do is remove dash and look for why door is sticking, at a cost of 1200.00. I bought vehicle new and has 56000 miles. Does anyone have any ideas that might save me 1200 dollars. Thanks

 

Welcome to the forum... you could always do some poking around yourself and see what does and doesn't move while someone works the controls....
just removing a few of the lower kick panels my give you some access to the area...

 

Oh for the good ol' days when things were operated by bowden cables and vacuum actuators.