Hello,
I tried searching and did not find this exact problem. My truck, 98 1500 with the 6.5TD is not switching over to the dash vents properly. When you move the selector to defrost or to floor or a combination, it changes to the desired setting. When you select the dash vent only setting, however, the air comes out of the defrost, floor and dash vents. It worked properly last year in the fall. I looked around, but really can't see anything amiss. I am not even sure if this is a vaccuum operated system or an electrical one. Can someone please give me some info as to what to check and how to check it? Thanks.....


EDIT: I should mention that all of the fuses are ok in the panel and lately, the fan will just cut out and a "fonzie" on the dash right above the contorller is needed to get it running again.

Try here...:D http://www.dieselplace.com/forum/showthread.php?t=137017

Thanks, one of the control arms was off as well as the rod had pulled out a bit and the flap was stopping the floor vent from closing. I was able to get the valve back up into position and reconnect the arm. How long it'll stay like that I have no idea, and if it happens again looks like I'll have to take the whole thing apart. But for now at least it is working.