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  1. #1

    Default 1991 Suburban What could it be

    I tried to do some searching for this issue. I will do some more later but I am pressed for time today.

    I have a 91 Burb 2wd(158k) 350TBI. I just got this about a week ago. The defrost was actually working. The next day the blower motor stopped working. after tapping it it starting working again. Now the issue is the heat only blows out of the vents no matter what setting it is on. I am sure the problem is the vacuum line or lever(don't know proper name) that controls the position of the air flow is off.

    My question is where is it located so I can check it?

    Thanks in advance for you help. Like I said I will do some more searching on this myself as soon as I can get settled and can search like I want to.

  2. #2

  3. #3


    Thanks Naptime but the temperature is not the issue. I have heat and cold. The issue I have is where it comes from. No matter what setting I put it on(vent, heat, defrost etc), it blows out the main vents. I am trying to find out if there is a vacuum line or an actual lever that moves the air flow to the different positions and where it is located. I had a 96 burb that had tha same issue but is was just a loose and located in a very easy to get to spot. I have not looked under the dash yet as I am hoping to find an answer here first.

    Thanks again for the help.

  4. #4


    If it's the blend door, it's located under the passenger side dash, on a little mechanical rod from the temp control slider. It has some adjustment to it, and the end is a loop of wire held onto the shaft by a push nut. By getting overzealous with the temp selector and "slamming" it from one side to the other, you can make the wire push the push nut off and jump the shaft. The temp selector would get easier to move, and it wouldn't do anything since it's no longer attached to the door. My Suburban currently is jury-rigged with this connection because I had to figure out what the push nut was called and where I could get it. (Autozone, by the way, on their little spinning displays with nuts and bolts, and other small fasteners for sale)

    1991 Chevy Suburban 1/2 ton 2WD w/ chevy SBC 350-3/4 ton drivetrain upgrade w/4.10 gears 200K miles
    2005 Saturn ION-2 Stock 265K miles
    1982 Bronco, 1993 Bronco (sold), 1971 M35A2 Deuce and a Half

    There are 10 kinds of people, those who understand binary, and those who dont...

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  5. #5


    THANKS CRAWDADDY. I will check that out as soon as it dries up here in Ohio.

  6. #6

    Default I had a chance to look at things. I found to blend door and the lever that controls the air flow. I moved it around. It will flow out of the top but not very hard. It does however blow out of the bottom very VERY good no matter where it is set.

    My question is could it be the tubing(not sure if that is the right name) could be off and causing that not to flow right?

    Its cold and and I know the frost and ice is coming. I need to get this done before then.

    Thanks again for the help guys.

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