fitzydog

I know an earlier post last week or so was discussing this. I am only getting air out of the vent and moving the switch does nothing. It was a guy from Pearland,tx well I am just north and it is getting cold here in houston and I can't get the defrost to work still! I replaced the actuator thinking that might fix it but didn't. I don't know if the problem is in the switch or what? Thanks for any help. Aaron

cascar

Wow this is wild I thought I was the only one that this happend to. My 2003 3500 just did that on the weekend. I can here the actuator moving something as I turn it but it is not allowing any air to go up to defrost or down to heat the feat. Like you say it's stuck on vent, witch is very anoying.

If you find out how to fix it let me know, I'll do the same.!

TonyB

It's either the temperature blend door or the recirculating door (let outside air in the cab) The shafts break off the door.

At least for the '06 models (and probably more) DC has an upgraded air box.

You have to pull the ENTIRE register to remove & replace the door.

HTH....sorry to bear bad news

Tony

J BODY

key on, eng on or off. fan high, turn mode from recirc to outside air.......do you hear an audible difference between the two settings?

Highway 4x4

Sounds like ya broke the blend door. The entire dash has to be pulled to fix it. I never use defrost for that reason. Good luck.

Mark Hodowanec

So what do you do when your windows fog up? Any tricks to keep them from doing so?

cskal

I hope that's true... I'm sure that if mine went I'd be WAY out of warrantee.

bdewey

shaving cream not the gel works good as a cheap no fog solution

TonyB

Mine went at about 8k on the clock...

Mark Hodowanec

Cool - Got to remember that trick. The only cheap one I new of was to spit on the winshield (like scuba googles), but I ain't got enough spit!

fitzydog

I replaced the blend door last year it is not hard at all to do. For now I have just been pointing the vents upward and turning the switch to the fourth positon and letting the hot air blast upwards and a minute or so I am clear!

So everyone in Agreement to change the blend door AGAIN! Ok Thanks

cascar

From the pasenger side of the truck if you get a flashlight you can see inside the floor heat vent, mine will open to get some heat to the floor but still none up top to the windsheild, there are a few donikers if I look stright up but I can't move them manually might break them (plastic)

Anyone have the schematics of the heater system? or a link?

Forstner

Mine started to act up around the 40,000 mile mark, just as cold weather was setting in. Their was alot of posts about this, and it has been a problem since 2003. The trick on my truck is to completely shut the fan off, wait about a minute, then change the selector ****. Wait another minute for it to change direction, turn the fan back on. Voila! I guess that I'm lucky so far, this is my second winter in doing this. I was pretty discouraged when the unit initially failed and all the crap one had to go through to fix it. The airbag part bothers me.Anyway give this a try,it might just work for you for the present time. Turning fan off does allow the broken plastic part to move.
Good-luck