AC Issue, front not cooling, rear good

[lt1gmc]

My 2019 Denali suddenly quit cooling the front while the rear works perfectly. Found no leaks, evacuated, installed new expansion valve for front, evacuated again, held 200 microns vacuum for 45 minutes, recharged with proper charge. Blend door is operating correctly, goes total hot and back to lukewarm at coldest setting.
Anyone had issue with the heat recovery portion of the front ac lines?

 

[Joseph Garcia]

When you say, 'Blend door is operating correctly, goes total hot and back to lukewarm at coldest setting.', what blend door are you referring to? Is the volume of air flow the same at both the 'hot' and 'lukewarm' settings?

There are multiple blend doors, and perhaps, another blend door is causing the issue.

A quality bi-directional scanner would be real helpful is assessing the operation of all of the blend doors.

@swathdiver @Doubeleive may have some further troubleshooting suggestions.

 

[Doubeleive]

My 2019 Denali suddenly quit cooling the front while the rear works perfectly. Found no leaks, evacuated, installed new expansion valve for front, evacuated again, held 200 microns vacuum for 45 minutes, recharged with proper charge. Blend door is operating correctly, goes total hot and back to lukewarm at coldest setting.
Anyone had issue with the heat recovery portion of the front ac lines?

I have not yet had to mess with the k2 hvac box, but I would assume you could use a laser thermometer on the metal lines from the engine side of the firewall to confirm operation?
sounds like you might have already done that before jumping to the parts canon? have you visually checked the blend door/actuator operation is it moving all the way?