73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Interior & Equipment => Heating, Ventilation & Air Conditioning (HVAC) => Topic started by: Hok9 on October 10, 2016, 11:30:00 pm
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I just fixed the vent door (the little white plastic piece) and I can't get the other flap (the black one) to line up correctly. If I unhook it I can get the air to come out of the upper vents, but otherwise the air stays on the floor. Is their a way to get both doors to work together?
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Would you mind posting some pictures? I'm almost positive I'm working on the same thing currently.
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Did a google search and found this pic from another forum. It is exactly the same as what I am dealing with. The "hidden " door in the pic is black with holes on the top and bottom. That is the one I am trying to adjust.
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If I remember correctly there is a dual vacuum pod setup on the front side of the heater box. It is between the firewall and the heaterbox. There is a short section of vacuum hose that goes between a couple of ports and then there is the main vacuum feeder line to it. One pushes the mode door and the other pulls the mode door. That could be the source of your issue. You will need to check to make sure the diaphragms are not ruptured and check to make sure that short section of hose is in good repair. I am reasonably sure you will have to pull the heater box off to work on those.
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It seems that the doors are connected by a long screw looking rod. When the brown door moves it moves the black door too. I think I am just going to remove the black door. I only need the vent and floor anyway.
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Adjustments are made to the door at the top where the cables are.
Chris Lucas
73-87chevytrucks.com
squarebody.biz
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I wonder if this is what I need to work on. My heater won't switch to the defroster to heat my windshield XD
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Check and see if everything is moving as it should.
Chris Lucas
73-87chevytrucks.com
squarebody.biz
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That's the thing, I think something isn't moving that should be
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that door shouldnt effect defrosters. theres another door not shown, location is about behind the ashtray. its right where the horizontal duct meets the vertical shaft for the defrosters. my mud truck had a defroster issue i think it was missing a vacuum line put i was able to separate the two ducts and shove a 6" extension into the door to hold it open as theres a spring for it to keep shut. never got around to fixing it cause it was only an issue in the cold when i needed defrosters. to this day its still in there and the rigging was done 8 years or so ago