Question: Mis-directed air....?

[JohnnyV555]

I just found this website and hope to get some technical help with my 1996 C4.

My car is equiped with the "auto climate control". When I hit the auto button the A/C compressor kicks on , the air blows cold but I can not get the air to blow out the dash vents. Air is directed to the defrost vents and the floor. Even when I push the override mode on the controller to blow out the dash vents, nothing changes. I am not sure if the problem is the auto climate controller or what... Has anyone had this problem or know what might be the fix?

Thanks...JohnnyV

 

[jmccloud]

No air from dash vents

If there's inadequate vacuum to move the control vanes in the vent system, the default is to blow air out the floor and defrost vents (none out the dash vents).
There's a vacuum distribution block above the gas pedal. 96's had some softer rubber nipples that collapse. And the center screw comes loose too. But most importantly, remove the passenger side fuel rail cover in the engine compartment and inspect the check valve and the vacuum tubing above the #5 cylinder. If that vacuum line or check valve breaks (often does), there will be inadequate vacuum to feed the A/C controls and the cruise control. Does your cruise control work well?
There are many threads on this subject and you can find them using the ''search" tab at the top of the screen, just to the right of center. Topics like A/C controller or A/C programmer or A/C vents, etc. will yield lots of good reading and advice. Many of these threads have excellent photos too.
Good luck and welcome to a really informative site.

 

[JohnnyV555]

Thanks for the direction for the mis-directed

The cruise control works fine, actually everything works on the car perfectly accept this one problem. I will take a look this weekend!!

Thanks...JohnnyV

If there's inadequate vacuum to move the control vanes in the vent system, the default is to blow air out the floor and defrost vents (none out the dash vents).
There's a vacuum distribution block above the gas pedal. 96's had some softer rubber nipples that collapse. And the center screw comes loose too. But most importantly, remove the passenger side fuel rail cover in the engine compartment and inspect the check valve and the vacuum tubing above the #5 cylinder. If that vacuum line or check valve breaks (often does), there will be inadequate vacuum to feed the A/C controls and the cruise control. Does your cruise control work well?
There are many threads on this subject and you can find them using the ''search" tab at the top of the screen, just to the right of center. Topics like A/C controller or A/C programmer or A/C vents, etc. will yield lots of good reading and advice. Many of these threads have excellent photos too.
Good luck and welcome to a really informative site.

 

[wannaC6]

info provided to me - may help you

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I just fixed my 96 today with the same problem.....air blowing out defrost & floor only. There is a black box right above the gas pedal with several colored lines coming from it. This is called the vaccum programmer . It controls which doors open up from your control on the heater, ac control..
ok back to the black box...I found the easiest way to work on this without breaking you back is to remove the drivers seat and disconnect the electric on your seat if you have a power seat'''only 4 bolts holding it on.This gave plenty of room to lay down and look up.After removing the the seat, get a flashlite or droplite and lay on your back and look for the black box right up over the gas pedal Look for the green connecter which your colored vaccum lines are coming from.make sure the green thingy is tight against the box and all the vaccum line are intact, put a bunch of pressure on the connecter and sqeeze hard and at the same time have someone work the heater controls . Start it up and set on auto-60 degrees and see if air blows out the dash..Some times the problem is a loose connecter..they are real flimsy..
Unfortunetly on mine my programmer was shot and I had to replace it with a new one...PART # 16227376 FOR MY 96..It was expensive too....$1059.38..I got mine from a freind from a chevy dealership that happens to be parts manager..got it for $582.66 plus a $25.00 core charge. I think they are cheaper for 1995 and earlier models...
Before you start anything check to see if there is anmy codes that come up on your heater ac controls...To check for codes do the following..........
1/........push the up and down fan button at the time and wait till the ttemp goes to 00.and then release and hold the fan button in between the arrows and see if any codes come up.....If codes come up then you will have to find out what it is....maybe on the web or dealer....or parts store.......
I hope this will help you out.............john............MY 96

 

[wannaC6]

one more tip from another member

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Well guys, I finally got around to removing the driver seat and contorting under the dash to find the cause of the non-functioning air direction control. Going to the controller box vacuum line connection that most recommended,I found nothing wrong. I removed the box and found that a pesky mouse had eaten through one of the vacuum lines connecting the inner vacuum line connector to the manifold and he chewed up the manifold a bit causing a hole in that two. After a bit of epoxy and CA glue all lines and manifold were repaired, system now works great! I just thought I would let you all know what I found. Probably a one off case, but if I had stopped at the vacuum line connector on the outside of the box I would have overlooked the real cause of the problem.

Guess the previous owner did not store in the best of conditions!
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