No air from defrost
I have this problem with my defrost that I would like to fix before it gets cold out. When I turn on the defrost air will come out on the first two blower settings but when I turn it higher than that I can hear what sounds like the door inside the vent closing and no air comes out. It will stay like this until i turn all the vents off(sliding the control all the way left). All other vents work like they should and the heat and "cool" works. Is that little door inside there vacuum actuated or does it have some mechanical linkage to open and close? I'll be tearing apart the dash tomorrow to fix it if there isn't an easier way to do it. Thanks JF!