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AC question: stuck heater flap?

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by Gryphon, Feb 28, 2010.

  1. Gryphon

    Gryphon Rockstar 100 Posts

    I think I have my answer, but I don't know how to fix it or where to look:

    My front ac blows whatever the outside temp is, the rear is fine. I refilled the system and plugged a leaky schraeder valve with a short bolt and Teflon tape instead of the plastic cap...no mo leak. (it will get fixed right, but it works fine for now!).

    When I'm driving with the blower off, I can feel the breeze from under the dash. Most noticeable on those really cold mornings ( as cold as so cal gets anyways). In the summer, I just get the outside heat rolling in.

    Where is the outside vent valve located on a 99 Burban? I've looked and found nothing and my Haynes manual...well, it's a Haynes manual.

    Thanks!
  2. ZSI52

    ZSI52 Epic Member 5+ Years 500 Posts


    My truck does this. From what Im told its the Temp door actuator. I guess some solder on the board becomes loose and causes a poor connection so the door stops moving.
  3. Gryphon

    Gryphon Rockstar 100 Posts

    Cool and not cool...if it's just a bad connection on a board, I can fix that easy...I've soldered plenty of circuit boards when I built silicon wafer processing machines.

    Does anyone know where this board is located?

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