a/c vent problems

[coxendine]

Hi guys, I am having problems with my heat/ac. Air only comes out the defrost and the floor vents. I dont think it uses vacuum to switch the air flow. Any suggestions

 

[JOSEPHJETT]

A/C problem Club...

I have the exact same problem with my 2007 Sierra. By switching to the defrost setting I can some times get it to switch the the dash but if I hit a bump or rough road it switches back to the floor or defrost again. I've been told that its a somewhat common problem with GM but have not been able to find advice for a fix yet (Other than taking it to the dealer and paying top dollar).

Any help/Advice for us out there?!?!?

 

[happy 2011]

all i'm going to say is as far as info goes... Garbage in garbage out. How can anyone tell you how it works if you don't tell us what it is............................

 

[sandman700]

I have an 02 that only blows out the panel vents. Turn the dial to floor or windshield and just keeps blowing out the panel.