on my 95 1500 truck, air blows out the defroster all the time. the actuators work and switch from floor, vent and defrost but always blows out the defroster and the desired positions as well. guessing something has fallen down the defroster vent and is not letting the defroster door shut all the way. does anyone know of the easiest way to access this door to see if something is jammed in there? do i have to take the dash apart to get to it? i'm sure this is a common problem, just really hate to tear the whole dash apart unless i have to