Air Vents not blowing???

[jbobrik]

I have a 05 6.0 and my air vents just stopped working. The only one it is blowing out of is the Defrost. I have the electronic control module in the truck, i've had trouble with this unit in the past but i changed a fuse an haven't had any troubles like this before. When i push the buttons on the module to switch to blow air on feet or face, i can hear it act like its working but the air doesn't change off of defrost mode. My other problem was the unit just wasn't working but it's fine now. Any ideas, thanks guys

[Blacked Out Outlaw]

I have the exact same problem. It's on and off though, not all the time.

[baddkarmaracing]

you have a vacuum leak somewhere the doors for the ac work off vacuum and ifs theres no vacuum they cant move i would check the lines at the hubs and see if they are cracked or anything

[MeltonUnlimited]

I took mine in when it was doing this, and they replaced a vacuum pump. That fixed the problem. Luckily it was covered by warranty.