Relearn Procedure for Rear Blend Door Actuators?

[Justinj360]

I just replaced the temperature blend door actuator in the rear of my 2004 GMC Yukon with auto climate controls. Before I replaced it I checked to see if the actuators were moving when I changed the settings. The mode actuator worked fine but the temperature actuator seemed to be dead so I replaced it. Nothing seems to happen with the new one either now. Even with the actuator just hanging there it still doesn't turn.

I'm wondering if there's a relearn procedure for the rear actuators? I've tried the normal relearn procedure but that didn't seem to do anything for the rear. I also pulled out the rear HVAC fuse at the same time as the front HVAC fuse. I figured doing that made sense at the time. Any ideas?

 

[Justinj360]

I followed what this guy did and tested the voltage at each wire. All of mine were good except for the yellow wires on both actuators were reading 0 (or very close to it). I'm thinking the control module is bad (part number 15185966) Can anyone help with this?

 

[HiHoeSilver]

I followed what this guy did and tested the voltage at each wire. All of mine were good except for the yellow wires on both actuators were reading 0 (or very close to it). I'm thinking the control module is bad (part number 15185966) Can anyone help with this?

I don't have any real info to add, other than in my research on rear heat not working, it seemed the control module was the common culprit.

 

[Justinj360]

I don't have any real info to add, other than in my research on rear heat not working, it seemed the control module was the common culprit.

Any info at this point is a huge help. I've come to that same conclusion as well. Before this, I thought the actuators were the most common failure with the HVAC.
Of course now that part has been discontinued by GM. My dealer is currently looking into some leads on a couple though. We'll see what they say.

 

[HiHoeSilver]

Any info at this point is a huge help. I've come to that same conclusion as well. Before this, I thought the actuators were the most common failure with the HVAC.
Of course now that part has been discontinued by GM. My dealer is currently looking into some leads on a couple though. We'll see what they say.

Not sure if you have the digital control or not, but I think it's one of these. There are a bunch....

 

[Justinj360]

Not sure if you have the digital control or not, but I think it's one of these. There are a bunch....
View attachment 221046

The part I'm looking for looks like this. I do have that too but it is different and for the blower motor or something. Unless I'm confused.

 

[HiHoeSilver]

The part I'm looking for looks like this. I do have that too but it is different and for the blower motor or something. Unless I'm confused.

View attachment 221047

You're probably right. Let me know if you find it. I think I need one to. Do you have the digital controls?

 

[Justinj360]

Well looks like Dorman has one:
https://smile.amazon.com/gp/product/B00KW743GS/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I was hoping not to have to go with aftermarket and especially Dorman because I've had bad experiences with their electronics. My dealers weren't able to track one down. Yes, I do have the digital controls.