Ll2001 suburban, when the AC is on, the front AC blows hot, warmer than ambient temperature while the rear AC blows cold air as expected. The flapper door seems to be working and both air box filters are new. What can cause this?

2004 Chevy Tahoe. Hot air out of vents on driver's side, cool ...

answers.edmunds.com > Edmunds Answers

Jun 25, 2009 - Hot air from vents-driver side and cool air from vents on passenger side. ... The driver's side vents were blowing out hot air, and everything else wasblowing cold. ... you'll literally have to restart your tahoe/yukon at every traffic light to keep cold air coming ... I was also getting air only out of the defrost vents.

Hot air out front drivers side vents 05 escalade - YouTube

? 3:14
https://www.youtube.com/watch?v=5lnd8UNcx6M
Aug 3, 2013 - Uploaded by South FL Mud Club
Suddenly hot air started blowing out the air vents only on the drivers... ... is a very helpful video ,I wondering if this part number apply for my 04 chevy tahoe? .... I have cold air out of thepassenger side, but warmer air out of the driver's side. .... 2003 Tahoe No Rear Heat Fix, Suburban, Yukon XL Repair!

Heating and AC Temperature and Air Delivery Mode Door ...

repairpal.com > Problems > Chevrolet > Tahoe

Driver/passenger air vents blow hot then cold when using A/C. Back to cold when you restart the vehicle. Upvote (35) ... 2003 Chevrolet Tahoe ... I have a 02 Tahoe ,and the heat system is working only on the ceiling side of the car when turn.

2004 Chevrolet Tahoe Blows Hot Air - Sparky's Answers

Blend Door Actuator Replacement 1999-2007 Chevrolet ...

? 2:25
https://www.youtube.com/watch?v=Eqf-H3COtSo
Nov 4, 2013 - Uploaded by 2CarPros
My problem in my 2004 chevy tahoe is that it will not blow out of the dash or ... onto the vent door gears ...

GMC Yukon AC and Heat Questions - Car Forums at Edmunds.com

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Jul 20, 2010 - 30 posts - ‎16 authors
I just don't get why that doesn't work right in the first place. ... I have 99 Yukon that has a problem with the front air. .... $55,000 for my GMC, I guess expecting cold air when we push A/C and getting 90 degree blast ... 2001 Yukon XL 1500 Front heat & air fine, rear ac blows hot as if heater is on in all settings. More results from forums.edmunds.com

I have a 2000 GMC Savana Van SLT with front and rear AC/Heat. My front would blow hot while the rear blew cold with AC on. It turned out to be low on Freon. It's hard to know if you have the right amount of freon installed because pressures vary depending on the ambient temperatures. So the best way is to remove all the freon then reinstall the recommended amount as listed on the evaporator housing near the firewall. This worked fine for me... works like new after installing the correct amount of freon.

There's a valve between the front and the back that is supposed to open automatically. I have the same problem on my 1994, but in reverse, I get AC in the front, but it just blows hot in the back. I was told that this valve might be stuck... but no one would tell me where it was or how to get to it and no mechanic wanted to fix it for me. Apparently, if you can find it, it's easy to get it unstuck. Good luck.

a plugged orifice will prevent the front from becoming cold

It is the AC vent door actuator.

The car uses the same freon in the front as it does in the rear. If the rear a/c is working, you either have a plugged evaporator in the front unit, or perhaps a bad heater switch. Try switching the heater to hot and see if it blows even warmer air from the front vents. If so, the heater switch is working and then it sounds like a plugged evaporator or maybe a plugged orifice tube. That is a good place to start looking. Hope this helps.

There is probably a temperature blend door in the duct-work under the dash that is inoperable or stuck in the heat mode.

I recenly had the same problem on my 1999 suburban, even after I replaced the whole ac system.
The heater valve, which is under the air filter area was not closing, causing heat to be blowing over the evaporator core. I used a zip tie to keep it in the closed position, and ac went from 70 degrees to 40. I think the vacuum switch is bad, 40 dollars (dealer part). You can also pull the vacuum hose off the switch, which is on the firewall and connect it dirctly to valve and it closes the valve, but fits loosley. Use silicone around vac hose if you go this route.

ase mechanic:
there are separate actuators for the blend doors. one for heat and one for cool. they work opposite and in conjuction with each other, if that makes any sense. ones open, ones close, for each different climate. sounds like the the cold one isn't opening in the rear.