2015 Yukon Rear A/C not cold

[matt1313]

I recently had my compressor fail when traveling. I was able to get it repaired and the AC is blowing extremely cold out of the front of the car. Unfortunately, the AC is blowing warm through the rear section of the car. I'm curious if it's the same system or a different system than the AC compressor. Everything I've researched shows it should be the same system and I can't understand why it would not be cooling on both.

Any insights would be great.

 

[Big Mama]

I believe you have a separate evaporator out back but share the condenser and compressor with the front. It’s usually behind the right rear tire.

 

[Doubeleive]

I recently had my compressor fail when traveling. I was able to get it repaired and the AC is blowing extremely cold out of the front of the car. Unfortunately, the AC is blowing warm through the rear section of the car. I'm curious if it's the same system or a different system than the AC compressor. Everything I've researched shows it should be the same system and I can't understand why it would not be cooling on both.

Any insights would be great.

the most common reason for rear not getting cold is a malfunctioning blend door actuator, but it could be other things.
a decent scanner would help

 

[matt1313]

the most common reason for rear not getting cold is a malfunctioning blend door actuator, but it could be other things.
a decent scanner would help

Thank you for the reply. I have a gds2 scanner but saw no HVAC DTCs. I relearn the actuators s. No errors. Any other suggestions that I should test or look for

 

[Doubeleive]

You can use the scanner to command the rear actuators, command them up/down and see if the temp changes & roof/floor direction air changes, you can check the temp with a laser thermometer harbor freight has them for like $25 or so, it's a tool that comes in handy from time to time, you can also use to check the rear ac line temp under the truck. The lines take time get cool, let it run for a while first then check

 

[matt1313]

You can use the scanner to command the rear actuators, command them up/down and see if the temp changes & roof/floor direction air changes, you can check the temp with a laser thermometer harbor freight has them for like $25 or so, it's a tool that comes in handy from time to time, you can also use to check the rear ac line temp under the truck. The lines take time get cool, let it run for a while first then check

So interestingly enough I did exactly this. I changed the temperature with the laptop. I checked what the laptop readings were for the temperature readings. I recalibrated the actuators and all the sudden it started working. Don't know what it was but it seems to be working now but thank you everybody for your help.

 

[Doubeleive]

So interestingly enough I did exactly this. I changed the temperature with the laptop. I checked what the laptop readings were for the temperature readings. I recalibrated the actuators and all the sudden it started working. Don't know what it was but it seems to be working now but thank you everybody for your help.

sometimes the actuators can get stuck, either just random or because the actuator is failing.
if you ever open one up it is just a little motor and plastic gear/s with a couple copper feelers that run across a contact line, it works by resistance value as it moves from end to end
the contacts get dirty over time, but the plastic gears also wear so fixing one is iffy.