air vent control

shallenn · Post by **shallenn** » Tue Sep 14, 2004 6:39 pm

i have an '02 sonoma, no matter what i change vent to-face, floor, defrost- it always blows out the face and i think the defrost also. when blower is on high there is a loud air turbulanse under cowl in the middle. don't know if its related or not. any similar problems or solutions?
shallenn

Post by **HenryJ** » Wed Sep 15, 2004 4:48 am

Seems like I have seen something similar somewhere, but I can't remember where.

First thing that comes to mind is a bad vacuum leak. The heater functions are vacuum controlled, so without vacuum the different modes will not change.

You might open the glove box and disconnect the red vacuum line to see if it is receiving vacuum during defrost selection.

And try the grey line, it should have vacuum all the time. It operates the non-existent auto climate control.

And ...

welcome aboard.

robbtodd · Post by **robbtodd** » Wed Sep 15, 2004 5:34 am

I have an 2002 S-10 CC. My S-10 just started doing the same thing. I have added a cold air Intake, new gibson exhaust, and a performance chip. I did not notice it until I put the performance chip on so I took the chip off last night but it did not help. If you find out why this happens, let me know.

Post by **HenryJ** » Wed Sep 15, 2004 6:17 am

P.S. make sure ATF from the transfercase is not entering the system, as some have had this problem when the transfercase vacuum control seals failed.

Maximous · Post by **Maximous** » Wed Sep 15, 2004 8:07 am

that is a GM problem, it happens on most trucks, when you put your chip in you probably disconnected a vacuum hose, same with the other guy, it is a vacuum problem, well actually lack of vacuum, thats why it cant turn the air from your face, it doesnt have the vacuum to close that vent, check your conections, or be lasy and take it in, on stuff like that it may be better to look under the dash and just see what you see, i fixed mine in my car, i fixed it in the dealer parking lot right after it had been "fixed", and still didnt work

robbtodd · Post by **robbtodd** » Thu Sep 16, 2004 4:11 am

I went to the dealership last night about several issues with my truck. The A/C problem is common on the S-10 and it is covered under warranty.

Hirolln · Post by **Hirolln** » Tue Sep 21, 2004 4:41 pm

HenryJ wrote:P.S. make sure ATF from the transfercase is not entering the system, as some have had this problem when the transfercase vacuum control seals failed.

This is what is happening. Same thing went on my crew. Take to dealer and let them warrenty it

shallenn · Post by **shallenn** » Fri Sep 24, 2004 9:10 pm

took it in and it was nothing more than a bad control knob... thanks for the help!