Blend Door questions...

[rsparrish82]

Hello all..

As I go farther down the spiral with my 2003 Yukon Denali, I have discovered a few things pertaining to the HVAC system. Im just looking for further validation before I decide to either dig in, or send it to a shop.

I performed the HVAC reset, which actually fixed a few things, but one it did not was the passenger side front. with heat or AC set to max for both, the passenger side front vents only blow mediocre heat, and mediocre fan, while the drivers side and floor (on both sides) blows super hot or cold respectively. Based on what ive been able to research, this is caused by the blend door actuator in the center of the dash. I have run through enough settings on the climate controls to verify that the passenger side front facing vents are the only ones affected.

As for the rear... i strongly believe the hot/cold blend actuator is bad. All other functions (fan speed/ vent selector) work fine, just no heat... not super cold, but luke warm at best. I realize this could be the heater core back there, but there are no leaks that I can see. I am going to do further testing with this one, as i want to remove the rear panel and have someone operate the controls while i watch the actuator move (or lack of).

I am certainly not excited about the front actuator being bad since i will have to take the dash out to replace it. Which is why I am asking here. I know there are a lot of threads on the HVAC systems here, and this is actually where i got most of my info. I just wanted to ask the great collective here what you all think.

Thanks for your input!

 

[mikez71]

Dash removal actually came out easier than I thought, just time consuming.

A scanner might help diagnose actuators. It will show commanded and actual position.

Keep us posted!

 

[rsparrish82]

Dash removal actually came out easier than I thought, just time consuming.

A scanner might help diagnose actuators. It will show commanded and actual position.

Keep us posted!

Will do. I will probably tackle it once i get more time off work. Since the seasons are changing im not incredibly worried about it immediately, but it will get looked into soon.

 

[mikez71]

Oh BTW, you're in the 07-14 section. So I have no idea about the dash on the '00-'06..
But some parts seem easier to remove than the 07-14.. The door panels are easier, and the dash surround is easier anyway..

I think you're right about the actuator, because you should still have cold A/C if it was something with the heater core.
I thought mine wasn't working in the rear, but I think I just didn't burp my cooling system enough at that time..
(yet I still have a code for the rear control circuit B0429)
If you're scanner only does engine codes, then you might not be seeing body codes..

 

[Doubeleive]

Hello all..

As I go farther down the spiral with my 2003 Yukon Denali, I have discovered a few things pertaining to the HVAC system. Im just looking for further validation before I decide to either dig in, or send it to a shop.

I performed the HVAC reset, which actually fixed a few things, but one it did not was the passenger side front. with heat or AC set to max for both, the passenger side front vents only blow mediocre heat, and mediocre fan, while the drivers side and floor (on both sides) blows super hot or cold respectively. Based on what ive been able to research, this is caused by the blend door actuator in the center of the dash. I have run through enough settings on the climate controls to verify that the passenger side front facing vents are the only ones affected.

As for the rear... i strongly believe the hot/cold blend actuator is bad. All other functions (fan speed/ vent selector) work fine, just no heat... not super cold, but luke warm at best. I realize this could be the heater core back there, but there are no leaks that I can see. I am going to do further testing with this one, as i want to remove the rear panel and have someone operate the controls while i watch the actuator move (or lack of).

I am certainly not excited about the front actuator being bad since i will have to take the dash out to replace it. Which is why I am asking here. I know there are a lot of threads on the HVAC systems here, and this is actually where i got most of my info. I just wanted to ask the great collective here what you all think.

Thanks for your input!

the front passenger side should not require the removal of the dash the actuator is under the passenger air bag. rear is easy-peasy

 

[Fless]

Thread has been moved to the correct year section.

 

[rsparrish82]

the front passenger side should not require the removal of the dash the actuator is under the passenger air bag. rear is easy-peasy

Perfect, thank you! i will look into it this week since my Yukon is down until I get my gauge cluster back from rebuild.

 

[waveryd]

I just replaced the blend door actuator and recirculation actuator in my 2004 Yukon XL. The dash pad must come off. Removing the radio and HVAC controls give you a little more access. You will have to tilt the defroster duct up out of the way to get at it. A flexible shaft for your 5.5 mm socket will be helpful also. Snap-On (and probably others) has an angled ratcheting wrench which is helpful in this situation also. Not an extremely difficult job but it is time consuming as stated above. Totally worth it whenever you are finished and everything works like it's supposed to. Since this job is a pain I only recommend using OEM GM blend door actuators. Definitely want to verify free movement and sealing of the blend doors also. As stated above the rear is pretty simple just time consuming removing all the trim panels.

 

[rjdjbd]

‘Hello all..

As I go farther down the spiral with my 2003 Yukon Denali, I have discovered a few things pertaining to the HVAC system. Im just looking for further validation before I decide to either dig in, or send it to a shop.’


Probably won’t be much help to you but I had a very similar issue with my 2012 Jeep Liberty. Replaced a few things, including the actuator doors and no help. But then I did a suggested heater core flush, nothing fancy, but straight-forward to do. I was expecting a lot to come out since my Jeep has 100k on it, but disappointedly, not much came out. (Sand-like sized debris came out.) Woo-hoo! It actually solved my issue and my Jeep with no heat is back to as-new. Easy to do, might be worth the effort.