Rear ac only blows hot.

[Gbrew]

Hello I have a 2006 yukon denali xl. Our rear ac only blows hot. I replaced the the damper switch I think it was called. (The flap that directs airflow over heater core or condenser). That did not fix the problem. After a little more playing around I found out that the one that directs air to either above passengers or at the feet also dosent work. I replaced a square controle module with a grey and red connector on it and that did not help as well. I have watched videos and all have pointed to these to items. Am I doing something wrong replacing them or is there something else that could be wrong.

I am trying to post pictures of the parts I have replaced but having trouble. I will get them up if need be.

Thank you.

 

[ccyt]

Your rear ac system might need to be clean out and re charged again, both front and rear work out of the same compressor but the are two different systems


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[RobbysDad]

Did you change the rear blend actuator? They have 4 of them and they all look alike being identical, but they are all different.

I have changed tons of these and they are a total problem. Start out by hearing a click and then the problems begin.

The rear is located under the right side under the back window under the big panel... Easy to change and make sure you pull the right p/n off the old one... Very Important.

Here is how you do it... Take off the strip that is under the cargo door and it just pulls up being held on by clips.... Then you need to get at the big plastic going up on that side too and remove....Then you can pull that big panel off and it is right there and do not need to take that big panel off all the way... You can access it real easy... Two screws which are either 8 or 6mm... A plug that comes out easy....

Just get the right one and then put it in and do not turn it or anything like that... Make it fit the way it comes right out of the box they are all calibrated already. Very Important.

What is happening is yours is stuck to only open the door to blow heat and some get stuck in the middle, some get stuck in the AC, or some just go crazy doing whatever they want until they finally break...

Just reverse the steps and put it all back together and you should be all good and make sure you get p/n off old one to get new... Total time is about say 20 minutes or so doing your first one after that you could do it in like 10...

Super easy...

Oh yeah... Their are 3 in the front... One controls which side gets the heat and cool where you could have heat on one side and cool on the other located under console.... Other is behind glove box which controls where the air blows... defrost, vents, feet....

The third is on the fan and I have never changed one but heard it is a total project due to you need to pull the dash to get at it...

These are always a problem and start with clicking usually, then the weird stuff with what it does, then goes out stuck....