I have a 1993 GT and when I turn on any of the temp controls, whether it be the a/c, the vent, or floor all air comes out of the top defroster vent and the floor, no air comes out of the middle vents. the A/C is cold and the heat is hot but for some reason the air will not come out of the middle. Anyone have any ideas how to fix this on my own or know where I could find the answer. I really do not want to pay $62/hr for someone to connect a hose or something when I could easily have done it myself.