Rear ac not blowing cold

[cbibb]

I hope this is the right section to put this. I recently picked up a 99 denali, the front ac blows nice and cold but the rear ac is blowing warm air. I was under the impression it was all connected but I guess I was wrong. Any idea on what would cause this and how to fix it? Thanks guys

 

[sumo]

Possible that there was a leak in the rear ac lines and someone probably installed a rear ac block off plate to prevent freon from leaking out

 

[cbibb]

Thanks for the reply. Is there any way for me to try to find out if they did that? Or does it need to go to a shop to get checked out? I just got this truck last week. I may be mistaken but i could have sworn it was blowing cold ac from the rear when i first got it, but was blowing warm from the rear vents today

 

[HiHoeSilver]

Could be the blend door actuator. It's behind the interior panel on the pass side in the cargo area.

 

[cbibb]

Thanks ill check that out as soon as i get a chance. Once i get to it is there any way to find out if its working? Assuming maybe i can manually move it??

 

[Bowzer]

Could be the expansion valve stuck closed or plugged with debris. It's near the rear coil. You'd have to take the charge out to disassemble and check it.

 

[sumo]

Could be the expansion valve stuck closed or plugged with debris. It's near the rear coil. You'd have to take the charge out to disassemble and check it.

Yea if you don't have the proper equipment to evacuate your ac system, you should have a shop do it for you. Not only that it be difficult to properly recharge your ac system to proper spec.