Rear ac on 05 tahoe just quit

[SteveCZ28]

ok its been very hot and muggy where i live lately, been using front and rear ac to help cool the truck down rather quickly. well i was driving home the other day, had perfectly fine cold ac working from rear vents, then about 10 minutes into my trip, the cold went to hot. no matter what i did i couldnt get it to blow cold air again. i even switched the front controls to the rear and tried adjusting from the rear of the truck with no luck. i dont know what may have caused this. i found a similar thread but it was backwards to my problem, as he couldnt get heat from his rear hvac. obviously something broke during my trip home, but now i need to get this fixed as i now have a newborn baby, and dont want her to cook in the truck, so my rear ac working again would be very helpful. any input would be appreciated at this point.

 

[Yukonboy2014]

Mine do that too. Just click system off and wait a few seconds, then back on. Its a rear damper issue..it probably means its going out.

 

[SteveCZ28]

ok ill try that. what is, and where is the damper?

 

[JochenWoern]

ok ill try that. what is, and where is the damper?

The rear damper is on the right side once you open your rear hatch/gate, located behind the plastic trim. It is a big plastic box that has a couple of doors which open and close, based on the temperature setting. The actuator will open/close the damper door, adjusting it for hot or cold air to enter.

In my opinion, you either have a broken door that no longer opens or closes or a bad actuator which no longer will make the door move. (I replaced the damper housing with doors). Depending on where the door is stuck, you either only get hot or cold air.

I had this issue a couple of months ago and if you query for all my posts, you will find what I did. I would attach the thread but am on my phone which is a bit more difficult in order to find it.

You may also check the INTERIOR section where you will find a few posts regarding this issue.

Hope this helps.

 

[SteveCZ28]

The rear damper is on the right side once you open your rear hatch/gate, located behind the plastic trim. It is a big plastic box that has a couple of doors which open and close, based on the temperature setting. The actuator will open/close the damper door, adjusting it for hot or cold air to enter.

In my opinion, you either have a broken door that no longer opens or closes or a bad actuator which no longer will make the door move. (I replaced the damper housing with doors). Depending on where the door is stuck, you either only get hot or cold air.

I had this issue a couple of months ago and if you query for all my posts, you will find what I did. I would attach the thread but am on my phone which is a bit more difficult in order to find it.

You may also check the INTERIOR section where you will find a few posts regarding this issue.

Hope this helps.

awesome thanks for the great information. what could be my problem tho, being as it was cold for about 10 minutes, then went hot? could a door have broken and caused this? if it is a door is it easily accessible and replaceable?
ill check/test the actuator for it tomorrow as well, to see if it is even turning.

 

[JochenWoern]

awesome thanks for the great information. what could be my problem tho, being as it was cold for about 10 minutes, then went hot? could a door have broken and caused this? if it is a door is it easily accessible and replaceable?
ill check/test the actuator for it tomorrow as well, to see if it is even turning.

Most likely the turning mechanism for the door is broken, leaving it in the closed position and therefore not allowing cold air to come through. It is easily accessible but there are a lot of parts that have to come off first, as the complete plastic housing which the doors are mounted to is mounted at the very back. Frankly, it is a pain to take out and reinstall all the components, but I did it myself in about 3 hours.

As I mentioned earlier, go query for rear damper door replacement and I am sure you will find lots of info.

The part was 115 bucks at the local Chevy Dealer.

Let me know if you have any further questions.

 

[SteveCZ28]

well dug into this issue today. got covers off to look at the dampers on the rear hvac. noticed the temperature damper was kind of jumpy. but would turn ok if assisted with a flat blade screw driver. cycled the floor vent damper and that runs smoooth. so i was going to swap the dampers between the 2. took the damper off the temperature actuator. and the spindle for the door itself was loose and rattling. long story short, the spindle for the door is broken. i managed to split the hvac box open and got some epoxy and re adhered the broken piece. just waiting for it to dry. but i think i should be good to go when dried and put together.

---------- Post added at 03:29 PM ---------- Previous post was at 02:18 PM ----------

well heres another update. put everything back together. damper turned left, then right than SNAP. broke the end off the door again.....so where do i buy a replacement door?

 

[Yukonboy2014]

Local chevy dealer or on GM's parts direct website, I believe.

 

[SteveCZ28]

i found the entire box for $67. but i think ill need a control module as well, as ive been reading and found out that when the modules crap out, they ofter over turn the dampers, like what happened to me and snapped the end off my door.