Ok So from what I've read this is fairly common. My HVAC only blows air out the face and feet vents. I turn the knob to change it to defrost and it just springs back, no air will come out of the top vent to defrost (which is a huge pain in the arse right now). NO matter what setting I put it on it only blows out the face and feet vents. I'm not entirely sure its blowing out the feet vents even.
Anyways i checked the cable behind the switch onthe control arm, it bends when i put it on defrost, should it be going back into the sleeve? the cable doesn't move in and out of the sleeve at all, its like its pulled out to far and is now bending and binding up. Is this suppose to be happening?

Also I read it could be a vac line problem... how would i know if its the vac line or just a bad cable?

I've read each thread on this topic back to 2005 and I haven't got a real definite answer as to what it could be. If anyone had pictures or diagrams of what to look for it would be greatly appreciated!

Also another common problem (must be a 2003 cavalier thing) my speedo gets stuck, but I figured that one out, getting a new cluster.

Thanks to everyone who can help, maybe this can be made into a sticky.



http://www.cardomain.com/ride/857357

The cable should not have any kinks in it. If it does it needs replaced. The most likely cause of this kink would be due to the foam seal on the vent door. You will have to remove the dash pad to get to the top of the HVAC assembly. The seal needs replaced. Once you have a new seal and cable you should be all set.