Just got finished fixing this problem in my 2005 Explorer. After checking all the vacuum hoses, it turned out to be the "mode" door.....NOT the blend door. It looks like there was a small 3/16" plastic "pin" on the door that the vacuum actuator moved forward and back to control the door. The pin was broken off completely. I drilled out where the pin was and tried to put a screw through it.....no where near enough patience to do that, so I just used some good ol' bailing wire.....I ran it through the hole in the actuator and the hole I just drilled.....twisted the wire together and cut off the excess and viola....I now have air that comes out where the selector dial says it should.
Paul
BTW 1st post, hope it helps...
