Yukon 2008 Denali - Rear air blows only hot air

[jpalmer99]

The rear air in my 2008 Yukon Denali only blows warm/hot air. Front air on both sides is fine.

There are a good number of posts concerning the rear control module and blend actuator, but the posts are written about models in the early to mid 2000's. Does anyone know if this same information is applicable to later model Yukon/GMC's?

I'm also trying to find what part(s) I might need but again I only seem to find the parts for the early to mid range 2000 models.

I'm going to try and reset the system tonight (pulling the fuse method). Any ideas, or verification that the steps are still valid, are welcome. Thank you.

 

[jpalmer99]

Did some more troubleshooting and everything works for rear air, ceiling and the floor, etc. except for the cold air. And when I go from hot to cold from the rear controls the air sounds different which makes me think the blender/actuator is doing something.

I felt the lines under the passenger rear corner and they are not cold, which makes me think there might be a problem with the orifice tube filter being clogged up. Anyone have any other tips to troubleshoot? Those lines should feel cold right?