I have a 1994 Grand Caravan SE, which will not blow air out the vents properly. If I set the air to blow out the vents it will work until I accelerate, then I can hear a flap slam shut and the air diverts to the floor. I can then switch it to defrost but not back to the vents until I come to a stop. I have searched the web for hours trying to find any information on the system that controls the air direction, but have had no luck. Any help, or a point in the right direction would be greatly appreciated.

 

I'm having the exact same problem, with the exact same van except mine even does it when I'm stopped now. It used to only do it up long hills on the interstate, but apparently something has gone out and now it just switches as it feels necessary. I was told by a friend to check the check valve attached to the break booster, but it appears to not be gunked up or anything.

 

Anybody have any ideas? If not is there a suggestion perhaps other than the stealer? The one thing I've noticed is, that when I do get the flap to reset, that I hear an electrical switch right before it works properly? Any takers on this one?

 

Any ideas folks? I've checked for vacuum leaks and haven't found anything.
Thanks.