Hi and thanks in advance for reading this post. I've been driving my '87 GTA almost daily since I returned it to the road a few months ago. 305 TPI/Auto, digital dash. I've charged the AC with R12, and replaced the blower motor. It doesn't matter whether I select Max AC, Norm AC, Bi-level, or Heater...most of the air blows up against the windshield and not through the vents. Any ideas for repair? Thanks in advance, Steve halfmoontrail@yahoo.com

THE VENT DOORS ARE CONTROLED BY VACCUM,LOOK FOR A LEAK UNDER THE DASH OR BEHIND THE CONTROL PANEL .

Thanks for your reply. Is the vacuum from the engine? Do I need to look under the hood, or from the pass. side, or the drivers side?

I appreciate the help.

Steve

I'm interested in how you fix this because I have the same issue with my camaro

The vacuum line from the engine enters the firewall on pass side, just about where last spark plug is, close to edge of heater box - it is bundled there with the wires that control the fan on the heater box.

On the inside, remove the radio bezel, and then remove the heater controls - you'll see where the vacuum line runs into the heater controls, and where the heater controls 'sends' this vacuum through a round switch looking thing on the right hand side that has several vacuum lines in different colors coming out of it.

These are the places to look for the leaks.

I've had problems with mine doing this, but it wasn't for lack of vacuum. From sitting for long periods of time, the damper doors get stuck. I was able to free mine by playing with the controls until it broke free. I now leave the controls in the vent position with the fan off so that the door has to operate every time I start the car.

If you can hear a hissing sound when you move your selector switch you need to replace the round thingy as mentioned above it is called a selector valve part#16032395 your control is going to default mode. The valve controls what vent air comes out of.

Here's what the selector looks like:

http://www.thirdgen.org/techboard/at...duct010707.jpg

A leak at the valve (or anywhere else )causes the default setting: defrost.

JamesC

I'm new to this site and need help locating this 16032395 vacuum selector valve for my '91 z28. I've tried to locate it variuos ways with no luck. Does anyone know where to purchase one?

Autozone or any parts store should have it or try gm parts direct or napa. Just make sure u connect the right hose back to the right connection on th new one.

If u have a pontiac it may go by a different part number