in my camaro i can't turn the front defogger off. When i slide the lever is does nothing. i have heard that it could be some sort of vaccum line or somthing could this be? if so were is it exactly is it and how to fix it would help. any pictures would be great.
thanks

 

If you switch from cold to hot (with the engine running or just after turning the car off), you should hear a little 'pssht'. If you don't hear this, you're not getting vacuum at the HVAC controls. If all vacuum is lost to the controls, the default position of the vents is for air to blow out the def.

Next to the blower box (big black plastic thing) on the pass side, you should see the heater hose(s) running into the firewall. Just below them are 2 small black plastic vac lines. One runs to the heater diverter valve (looks like a mushroom with 3 heater hoses attached), the other runs to the throttle body for vacuum. Check these to see if they are in good shape and connected.

If those are in shape.. next place to look is the controls. You'll need to pull the HVAC controls out (which can be a little tricky) and make shure when selecting vents, the vac. diverter (has all the colored lines running to it) is being moved with the lever. There is a small plactic tab connected to the control lever that switches the diverter, sometimes this can break leaving the diverter stuck in one position.

If it seems to be (mechanically)working fine, start the car and listen for a hissing sound from it. If no, the line from the engine bay to the controls is bad somewhere. If yes, the diaphragm (sp?) may have finally worn out and replacing the controls (or just that valve) from a donor car is the only real solution. Or, you can be a brave soul and take it apart. There's some form of wax coating (parafin maybe ?) on it to help the seal.

 

thanks for the help. i fixed it.

 

No prob.. glad you got it fixed