Defroster problem 1993 C3500

[Lil Timmy]

I've not been getting any air through the defroster vent since I bought this truck a year ago. When selecting the defrost mode, I can hear it switch over and can hear the air blowing in the dash, but no air coming out the vent. Is there an easy way to the vent door/flap, or will fixing this involve ripping the whole dash apart? Anyone know?

Thanks!

[azblazor]

Is there an easy way to the vent door/flap, or will fixing this involve ripping the whole dash apart? Anyone know?Thanks!

I have just finished removing and re-installing the whole heating/AC underdash assembly in my 1996.

There is more than 1 damper to reposition to get defrost.

Obviously at least one is not positioning correctly.

There are 3 electric "motors" that do the repositioning of all the air ducts.

2 of the three are accessable without removing the whole assembly.

You might also have an issue with the dash mounted "Control assembly" below the radio.

[Lil Timmy]

After reading your tips and a few from the full size Chevy forum, I delved underneath to see what was up. As it turned out, I only had to remove the radio head unit to find the problem. The arm for the electric actuator had come off of the pin for the defroster flap. A nice 1/2 hr fix and no busted knuckles!

Thanks again!