All air movement only comes out the dash bi-level vents. This is for the 99' S-10 with 4.3 and 4-wheel drive. A friend said that this 99' model has two air flow divertion-motor controls. Both are under the dash & hard to get at without tearing the whole dash out to find the correct one.

Hoping for a simpler opinion than that.
Thanks in advance
Joe

 

From what you're describing the problem definately sounds like the issue is with the air diverter control. It also sounds like your friend may very well be correct.

Good luck.

 

I had a similar problem with a GM. My problem was that I had a vacuum line cracked under the hood. As soon as I fixed the line i had full control of it and my cruise control.

Just another thing to look at.