When I'm driving I have no trouble going from heat to A/C or redirecting the air flow to where I need it, all the vents appear to be working correctly. But after I shut the engine off I can hear loud creaking under the dash toward center and right of center. The weird thing is the noise and movement usually starts anywhere from five to thirty minutes after shut down. The first time it happened my wife was sitting alone reading a book in the passenger seat and it scared the hell out of her. I'm new to this truck and I don't know my way around it very well but this can't be a normal condition. Are there some parts that need replacement or lubrication or adjustment? Any help would be appreciated. Thanks
Earl
Earl