[stuartnh]

I have a 2001 Windstar. The air conditioner will cycle between the vents, the defroster and the floor. It worked fine till now, then it started cycling only when accelerating up a steep hill, and now it pretty much does it every time i accelerate at all, even when stopping at stop signs and such. It will blow through the vent, which is normal, and then cycle to blowing through the defroster for maybe 10-20 seconds and then will cycle to the floor and finally back to the vent. As long as i'm just driving down the road on flat surface, it seems to work ok. I'm pretty sure it's some kind of vacuum problem, as i think everything is vacuum operated in the climate control. Anybody have any ideas or had this particular problem before?
Now it just goes to the defrost.