Dodge

At least i suspect a vacuum problem. when accelerating air venting will switch from defrost to dash or floor and back again when driving normal. is there a common failure, where do i begin to look?

Its a vacuum problem, i helped mine a lot by torquing the intake manifold. each bolt took at least 1/2 turn before the wrench clicked now my cruise control & heater controls work a lot better. be sure & check all your vacuum hoses & cut off any split ends or replace the entire hose.dont forget to check your power brake hose.