AC / Heater / Defrost Vent Problem

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by Chuck, Apr 24, 2006.

  1. Chuck

    Chuck New Member

    I have a 1995 Suburban 1500.
    My airflow is stuck in the floor position no matter what setting is switched on the dash vent switch. I can't get defrost or dash vent air to work. Fan settings do work. Also, there is no light coming on when the AC button and/or the recirculating buttons are pushed. All fuses look good. When the AC button is pushed, it doesn't appear to engage the compressor.
    What could be happening?
    Can't drive around without defrost. Too dangerous.

  2. Guest

    Guest Guest

    In most cases the flap that directs your air flow, is controlled by vacuum lines, sometimes it's a cable. You may want to check to see if the vac line is still connected. unfortunately you will probably have to tear the dash down some. 84fiero has a better handle on these issues. Maybe he'll swing by, and add some thoughts.

    Of course if you have young children, you could be the victim of the lolipop in the vent, or some other foreign object that got lodged in there.

    Sorry either way I think you're going to need to do some exploratory surgery.

    Good luck, and keep us posted. :D
  3. Chuck

    Chuck New Member

    One other thing...
    There is a motor assembly next to the gas pedal and attached to the air handler box which appears to control the linkage for the "flapper" or "baffle". What is it called? Any how, I pulled it off and checked it out and appears to be working fine. Would there be a separate vacuum system?

  4. k9cop

    k9cop New Member

    Is there any more input on this. Mine will blow out defrost and floor but not the front of the dash. HELP I'm melting!
  5. mitch2264

    mitch2264 New Member

    I am not sure

    but reading your description I would suspect the heater a/c control assembly. I have read several posts on other sites that pointed to this. Supposedly these tend to malfunction and do weird things. Mine is squirrely too. If system (fan switch) is off and I just have it on vent, the outside air mostly blows at your feet. Sometimes it will come out of the dash vents. If the a/c button is pressed in but fan selector is off the amber a/c light will be on sometimes or just flicker. I checked this part at LMC and it shows the '95 using a control assembly that is unique to just the 95 models. It looks like the same one as the 96 to 99 models.
    Good luck! I did find a post where a guy had detailed instructions on how to rebuild this unit using parts from Radio Shack --just soldering in some new resisters, etc.
    Last edited by a moderator: Sep 22, 2009
    1 person likes this.
  6. Cableguy

    Cableguy Epic Member 5+ Years ROTM Winner 1000 Posts

    Good advice, Mitch. I don't think your far off. I had to replace same thing in my work van.
  7. k9cop

    k9cop New Member

    When I switch to blow out the front it sounds like it wants to switch, but almost like the baffle is stuck inside the dash. I switch to defrost and I can hear the baffle move. It finally blew out of the front of the dash today. Not sure what happened, so I guess I just won't take it off that setting, :) .
  8. DSub95

    DSub95 New Member

    I have similar issues with my 95 Sub. I just bought it and noticed simsilar things like no light on the a/c or recirc buttons and I had no floor or defrost air just dash. I also noticed the a/c compressor was continuously engaged even if the a/c was off. I started looking at fuses and relays and found there was a jumper wire from the a/c relay (under hood) to a and ECM fuse just next to it. When I removed the wire, the compressor stopped. I replaced the relay hoping the $9 part would be the magic fix, but this did not change anything. I figured this was probably an electrical problem in the dash panel So here I am, looking for suggestions/answers. I did fix the "no floor air" problem. I found the harness to the damper by the gas pedal was unplugged. Now I get floor air only on "defrost" and "defrost/floor" but not on just "floor" but never did get defrost air other that the side window defrost vents.???? Another question: is there supposed to be some type of thermostat controller that keeps hot water from flowing through the heater core (front and rear)? This seems to keep my a/c from getting cold enough.:confused:
  9. SonofThunder

    SonofThunder New Member

    Where is that post about the guy rebuilding this unit?
  10. winterwolf

    winterwolf New Member

    Try this,

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