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.
Of course to get that unit out requires dismantling the dashboard by removing the cowling from the kick panel at the bottom to the front panel that goes almost 2/3 of the way across the truck.
I have done this before on our previous truck, a 1999 Chevy S10 (except I was replacing the radio), so I wasn’t too intimidated. In fact the 2003 GMC Sonoma we just bought was a bit easier because the parking brake pedal and release mechanism are now made to be disassembled easily. Not like the S10 where I needed to be a contortionist and know the secret password – which I didn’t. And that release cable had to be disconnected so the kick panel could be moved enough to remove the screws that were holding the steering wheel lower cowl in place so I could remove the screws that hold the main trim cowl in place. That has to be removed so I could remove the mounting screws that hold the AFCU in place and slide it out of it’s housing enough to disconnect the wires and vacuum lines that plug into it.
And let me just say that GM is mighty stingy with those vacuum lines. I don’t know how a person with normally sized man fingers would get in there to get the thing hooked back up. It seems the ideal person for this job would have fingers the size of pencils: diameter and length! An alien would be good. I’m almost as good because I’m small, my fingers are small. Short — but small enough to get in there.
Marie drove the truck in the dark for the first time yesterday and said the dash lights didn’t work. So while I had the dash all apart I pulled the instrument cluster and checked the bulbs. They were dusty but whole. I cleaned all of them and put them back in.
As of right now,
- the air flow controls are working again.
I do not hear that hissing noise.
- The engine idles better.
- The dash lights work.
- and I ended up with no spare parts. Tis not good when you end up with parts left over.
The check engine light is still on, but if it doesn’t go out in a couple of days (takes a while to clear the code buffer) I’ll take it to O’Reilly’s Auto Parts and have them read the computer to see what it’s saying. I expect it will be a fuel/air mixture error (because of the vacuum leak sucking air). They can clear the codes, which will turn off the light, and it should stay off now.
All of the dash controls seem to be working, so apparently I got the myriad of electrical connectors all properly connected up again – without accidentally triggering an air bag. One does NOT want to trigger an air bag while working on the dash. That’s a bad thing.
I am a little sore because wiggling around on the floorboards under a dash is still wiggling around on the floor under a dash. But I’m also feeling a bit accomplished, so I thought I’d crow about it just a little.