Tring to fix my rear HVAC. Hot/Cold change over not happening

[Kingfish585]

I got the same deal so il throw in my own issue. Ive replaced one of the blend doors on the passenger side but thats it. My rear only blows cold but the air director works fine. My climate control module is kinda funky, it will say 80 degrees but still be cool air as well as be blowing full blast on low setting. Im guessing il start with the rear control module and eventually replace everything.

 

[mizzouguy]

I got the same deal so il throw in my own issue. Ive replaced one of the blend doors on the passenger side but thats it. My rear only blows cold but the air director works fine. My climate control module is kinda funky, it will say 80 degrees but still be cool air as well as be blowing full blast on low setting. Im guessing il start with the rear control module and eventually replace everything.

Did you pull the actuator for the rear temp out or just watch it spin? On mine, the actuator was fine and the control unit was fine but the blend door itself had broken. Had to replace the whole housing.

 

[dhulsey779]

I am having the same issue with No Rear Heat. So after researching and reading reviews it seems as though the "Climate Control Computer" in the rear has failed. Ordered one up from Amazon and hopefully it will correct the issue.

ACDELCO # 15832319
Glove Box codes to refer:
CJ2 - A/C frt auto / aux cont
C36 - Aux HRT, RR
C69 - Rear Auxiliary A/C

 

[Kingfish585]

Did you pull the actuator for the rear temp out or just watch it spin? On mine, the actuator was fine and the control unit was fine but the blend door itself had broken. Had to replace the whole housing.

I did not pull the actuator out.

 

[Firm]

I recently fixed this on my 06 Escalade. First I took the rear access panel off and watched the actuator as a changed the temperature using the controls. As expected, the actuator wasn't moving at all when I changed the temp.

I ordered a new control module, and a new actuator and installed them both. I watched again while changing the temp and noticed that the actuator was now moving as I'd expect it too, but the air coming from the vents still wasn't changing temperature (I had HOT only).

I took the actuator out again, and touched the plastic rod that it rotates; that plastic rod is actually part of the blend door itself, and when I touched it I realized it was just 'free wheeling', it had broken away from the blend door itself.

I went to my local scrapyard, found a Yukon with rear HVAC and tore apart the HVAC box, taking note of how it all comes apart. I removed the blend door from the donor Yukon and took it home. Then I careful repeated the tear down procedure on my Escalade's rear box, installed the new blend door, and put everything back together.

It's actually a fairly easy job, but you need to go slow and take your time. There are lots of little clips to break/lose if you're not careful. You also need to be careful when moving/handling the rear heater core and lines, you don't want to mess those up.

 

[dhulsey779]

I am having the same issue with No Rear Heat. So after researching and reading reviews it seems as though the "Climate Control Computer" in the rear has failed. Ordered one up from Amazon and hopefully it will correct the issue.

ACDELCO # 15832319
Glove Box codes to refer:
CJ2 - A/C frt auto / aux cont
C36 - Aux HRT, RR
C69 - Rear Auxiliary A/C

Easy swap out and it works perfectly.


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