Where is the blend door

Did these two symptoms appear at the same time? If these two things started happening at the same time then I would suspect that the control module has failed. But HVAC and its components are not my forte for sure. Does anyone else want to weigh in?

Also I think we need the VIN number because there are several different sub-models all with a 327 (5.3L) engine available.

Hello,

Here is a great guide on the blend door actuator location: Even has a video :)

https://www.2carpros.com/articles/replace-blend-door-motor

Please let us know what happens.

Cheers, Ken

Thanks for that Ken. I have been meaning to get back to this question. I will be able to look a little more tomorrow.

So I did a "phone-a-friend" on this issue. Here's what we came up with.

Technical Service Bulletin (TSB) #04-01-38-008, issued by GM, deals with the issue of the air only coming through the defrost vents. Basically, there's some wiring behind the dash that is rubbing up against an edge. It has become damaged and is causing your issues. If this is the problem, you'll need to get behind the instrument panel (dash) and repair the wiring. Then, with the ignition off, pull the HVAC/ECAS fuse for a minute, put it back in, and then turn the key on for a minute (this is a reset/relearn procedure for the control head and actuators). After that everything should be ok.

Here's the TSB: http://www.justanswer.com/uploads/SKeel1221/2009-04-21_142349_hvac_harness_yukon.pdf

If that doesn't solve the problem, then you'd need access to a fairly high-end scanner (a tech-2 scanner) which most mechanic shops don't have (at least not in my area), but the dealer does.