Blend Door and Mode Door Replacement?

Tiny
HMAREK66
  • MEMBER
  • 2005 BUICK LESABRE
  • 6 CYL
  • AUTOMATIC
  • 111,000 MILES
Hello, I reviewed the blend door replacement article, and it was really helpful. I’m running into 3 items:

1. The passenger side air is not running cold (replaced the actuator under the glove compartment & can confirm that the air is cold when move the door manually). I have replaced this actuator and have not seen any difference in temperature, so I'm not sure if I did it incorrectly or if the HVAC needs to be reset.

2. The mid and bottom air is not switching as it is only pushing out from the floor vents (replaced the actuator under the steering wheel & can confirm that the air pushes out the mid vents when move the door manually). I have replaced this actuator and have not seen any difference in air coming from mid vents so not sure if I did it incorrectly or if the HVAC needs to be reset.

3. The driver's side air isn’t cold, and I have not been able to find that corresponding actuator.

My main questions are:
1. Do I have to reset the HVAC, if so, do I just remove the fuse and replace it?
2. How can I confirm if the actuator replacements aren’t faulty and if they are the correct ones? I got the 604-111 for 1 & 2 above
3. Where is the driver’s side actuator located so that I can turn the air cold on that side too?

If all this has been answered already in another post/ video, apologies in advance.

Thanks,
Hunter
Wednesday, July 9th, 2025 AT 9:51 AM

3 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Hello Hunter,

Yes, let's make sure you have replaced the correct actuator. Here is the location of the actuator on the right-side actuator. Also, I have marked the mode actuator in the images below as well.

RE-CALIBRATING ACTUATORS

CALIBRATION PROCEDURE
Use the following steps to perform the calibration update:
1. Turn OFF the ignition.
2. Remove the battery positive voltage circuit fuse of the HVAC Control Module.
3. Wait 60 seconds.

IMPORTANT: The module memory will not clear if the battery positive voltage circuit fuse is installed in less than 60 seconds.

This guide can help as well to reset the entire HVAC system.

https://www.2carpros.com/articles/step-by-step-guide-to-reset-your-cars-hvac-system-an-essential-for-every

Here are the fuses (37 and 34 in the rear fuse panel) you should remove. Check out the images (below). Please let us know what happens.

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Thursday, July 10th, 2025 AT 10:45 AM
Tiny
HMAREK66
  • MEMBER
  • 2 POSTS
Thanks for the help!

I was unsuccessful, but I’m starting to think that perhaps I’m not using the right actuators. Upon further review, I’ve realized that there are different actuators for this car, depending on whether it’s a dual climate system Or not.

I do not have a dual system and just have the slider to control the fan and temp. Do you know the part number for the temp actuator (passenger side) and mode actuator (drivers side)? I need to start there and ensure that the parts are correct before I try the reset again.

I cannot find the 3rd actuator that I believe controls the driver temp - picture attached. I see where I believe the 3rd actuator would screw into.
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Friday, July 11th, 2025 AT 5:34 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Yep, you are correct. This is non dual HVAC controls.

Temperature Blend Door Actuator (Passenger Side)
ACDelco GM Original Equipment: 15-72646
GM OEM: 89018365

and

Mode Door Actuator (Driver Side)
GM OEM: 52491800
ACDelco Replacement: 15-72647

Let me know what happens.
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Saturday, July 12th, 2025 AT 9:06 AM

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