Rear Climate Control

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diezelraccoon

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Been having an issue on my 03 Tahoe LT with the rear temperature control. It was stuck on cold and would not go warm. I ended up replacing the rear blend door actuator with a cheap aftermarket one. It worked for a while and then it stopped. I then replaced it with a doorman one and now I am still having the same issue sort of. I tried adjusting the temperature for the rear but it stayed on cold. I shut the vehicle off then start it back up and adjusted it over to hot and it slowly started blowing warm air but certainly not hot. Then I adjusted the air to flow knob from the top vents in the ceiling to the floor, and then back to the vents in the ceiling and then it started blowing cold.

I am really not sure what this thing is doing or what the issue is. If anyone has any input would greatly appreciate it.
 

S33k3r

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There are two pieces back there that control things:

The blend door actuator (as you already know)

This is a YouTube video on the rear, blend door actuator

The HVAC Control Module:
Screenshot 2024-11-13 at 7.53.51 AM.png

For the record, I just went and looked at my spare part to remind myself what that thing is called. I went out in 56 degrees F for you. Please value my sacrifice. It was uphill, both ways, from my garage to my escalade (there's a drainage valley between the garage and the driveway) and it was such a long walk (the 100 feet though the house and garage, and the 2 feet to the Escalade!).

Anyway, if you want to break out the parts cannon, that's the next piece of low hanging fruit.

If you are able and willing, you might troubleshoot the wiring all the way back there. A loose wire might cause similar symptoms. We had rear AC go completely out on our 2005 Suburban 2500 after a 20 year old wire broke on the passenger side, right around where the second row passenger seat sits.

Good luck.
 

adamztrucking

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Here’s a summary of steps to address your Tahoe's rear temperature control issue:

1. Recalibrate the Actuator: Disconnect the battery briefly, reconnect, and let the HVAC system reset.
2. Check HVAC Control Module: A faulty module could cause inconsistent signals; scan for HVAC-specific codes if possible.
3. Inspect Wiring: Look for loose, corroded, or damaged wiring to the actuator.
4. Check Blend Door Movement: Ensure the blend door isn’t binding or misaligned.

These steps may help restore consistent temperature control in the rear.
 

Doubeleive

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Been having an issue on my 03 Tahoe LT with the rear temperature control. It was stuck on cold and would not go warm. I ended up replacing the rear blend door actuator with a cheap aftermarket one. It worked for a while and then it stopped. I then replaced it with a doorman one and now I am still having the same issue sort of. I tried adjusting the temperature for the rear but it stayed on cold. I shut the vehicle off then start it back up and adjusted it over to hot and it slowly started blowing warm air but certainly not hot. Then I adjusted the air to flow knob from the top vents in the ceiling to the floor, and then back to the vents in the ceiling and then it started blowing cold.

I am really not sure what this thing is doing or what the issue is. If anyone has any input would greatly appreciate it.
my money is on if the 1st actuator worked fine (for a while) and the dorman failed in short order (but did work) then you might just bite the bullet and get a oem or hit the junkyard there all the same for 00-06 for all wheel base tahoe, yukon, esalade, suburban, yukon xl. this generation is plentiful in the junkyards
 
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diezelraccoon

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my money is on if the 1st actuator worked fine (for a while) and the dorman failed in short order (but did work) then you might just bite the bullet and get a oem or hit the junkyard there all the same for 00-06 for all wheel base tahoe, yukon, esalade, suburban, yukon xl. this generation is plentiful in the junkyards
Do you have a link to somewhere that sells the correct OEM one?
 

Fless

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If you think it's the Dorman one it should have a lifetime warranty, so you could return it to the seller and have them give you a new one.
 
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diezelraccoon

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Here’s a summary of steps to address your Tahoe's rear temperature control issue:

1. Recalibrate the Actuator: Disconnect the battery briefly, reconnect, and let the HVAC system reset.
2. Check HVAC Control Module: A faulty module could cause inconsistent signals; scan for HVAC-specific codes if possible.
3. Inspect Wiring: Look for loose, corroded, or damaged wiring to the actuator.
4. Check Blend Door Movement: Ensure the blend door isn’t binding or misaligned.

These steps may help restore consistent temperature control in the rear.
So this issue started after I reconnected my battery after it was disconnected for 3 weeks when I was replacing the rear main seal.

I ordered an OEM actuator and installed it and it didn’t work. I reconnected the Dorman one and it worked but still was doing same thing. I disconnected the battery and left it that way for about five minutes, then reconnected it and turned the key to the on position and let the system do its thing for about a minute then fired it up. Now the temperature control for the rear works. I am not sure exactly what caused this issue.

I do have another question. When you adjust it from hot to cold or cold to hot, it doesn’t switch over as quickly as the front. I noticed when you make an adjustment, the actuator turns a little bit at a time. Is they normal?

Also doesn’t feel like rear blows as hot as front. Is that normal as well?
 

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