Hey I have a 03 2500. The climate control blows hot and cold and the air conditioner works. But the **** that selects which set of vents the air comes out doesn't work. It only blows out the chest level vents. It used to work fine. I think its the defroster deflector door. To my understanding this is super expensive and/or time consuming to do yourself. Is there a simple fix? An easier way to do it? A way to "rig" it to work?

 

check under your hood for a small black plastic hose coming from your purge solenoid that goes into the fire wall. this is the vacuum that controls the door. if this is cracked it will not work. if this is not the case, then im afraid youll have to rip yyour dash apart. good luck

 

Sounds like a case of the infamous bad blender door. Do a search on here and type in "blend door" or "blender door". Should be more information than you'll ever need.