Our pick-up truck’s check engine light came on and it started running rough at idle a couple of days after we got it home from the purchase. Also, I started hearing a hissing sound in the dash. And the air conditioner stopped working. All at the same time. To me there was only one answer – and it was one I figured I could fix myself (for a change).
On the Chevy S10 and the GMC Sonoma the air direction control uses vacuum to pull bellows driven valves inside the dash to direct air to the feet, dash vents, or windshield.
I ordered a new Air Flow Control Unit from GMPartsDirect.com a week or so ago and it arrived a few days ago, but it has since been raining or Marie had the truck because her Subaru was in the shop.
Today I spent most of the morning replacing the Air Flow Control Unit.