Question about 1999 GMC Safari

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A/C coming out of defroster and will not go to any other settings

In the engine compartment I have found a loose vaccume hose near the firewall. This hose has a fitting coming out of the hose and I am guessing that it connects to another hose(the fitting is straight, plastic, approx 3/4").AsI trace it BACKWARDS, it goes to another hose. PLEASE HELP. I was in the Navy for 10 years (74-84) so my military mind will not let me quit untill I figgure the Damn thing out!!

Thanks in advance,

Art Kidwell (

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It is a loose vacuum line, and you'll just have to trace it by hand as to where it needs to go. You might be lucky and have a vacuum line diagram under the hood, or you could buy a Haynes or Chilton's manual for the diagram. Vacuum is what controls the dampers in the air box(s), and with that line being loose you aren't getting sufficient vacuum to move them.

Posted on May 27, 2009

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