My Ram, '91 model, flips between the defog and the dash vents when you start up a hill. It don't have to be much of an incline either, just 2 or 3 percent, just enough to put a little load on the engine. I've had it to the part changers over at the dealership and after $300 it is still doing the same thing. Now they want to put a $400 part on it, a gas canister. With it only doing it on an uphill slope it seems to me it would be a vacuum thing.
Anyone have any ideas?
KY