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1995 GMC Jimmy Question: Vents are stuck in heat,and defrost position

 

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murphtw, Lynchburg, VA, July 25, 2009, 07:25
 Rookie

When I use the Ac.it only comes out at the bottome,and the defrost ports.Same with the vent.

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  • Answer #1

    Russ July 31, 2009, 12:59
     Master

    The air delivery mode doors are controlled by vacuum actuators. I would suspect you have a problem with the vacuum supply lines under the hood. The vacuum source is located on the right rear of the intake manifold. The vacuum reservoir is attached to the left rear of the hood. Check all the vacuum lines for leaks and also inspect the vacuum check valve near the vacuum tank for proper operation.

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