The heat on my driver’s side sometimes stops working - blend door actuator?

Hello, I'm Danny.

The actuator is located on the HVAC box under the dash. Here is a basic tutorial showing what is involved for its replacement:

https://www.2carpros.com/articles/replace-blend-door-motor

After replacement you will need to perform an actuator re-learn procedure. I've attached the location and replacement steps below. Let me know if you have any further questions on this issue.Hope this helps and thanks for using 2CarPros.

No heat on the passenger side.

Hi and thanks for using 2CarPros.

Pictures 1 and 2 show the heater box under the dash and the legend of what each component does. You are looking for component 2 in picture 1. Picture 3 shows the actuator being removed. Picture 4 are directions.

Let me know if this helps or if you have other questions.

Take care,
Joe

The actuator cost me $84.00 all fixed

Glad I found this site. The rear AC on my 08 Tahoe LTZ was blowing hot. I finally got around to trying to replace the rear blend door actuator. I bought a new actuator from RockAuto several months ago. After I got the rear panel off, I saw that the two actuators were on the backside. I was able to change the top actuator with a 1/4" ratchet and T-15 bit, by just putting my hands back there and feeling around. I think I only fixed part of the problem though. It doesn't blow hot anymore. It blows cool, but not cold. But a definite improvement. Thanks for the help!

I understand this thread is over 6 months old, but I wanted to add my experience in case someone comes across this while in the same predicament.

I have a 2013 Chevrolet Tahoe and the Blend Door Actuator began making a knocking noise. (Once the key was inserted into the ignition and the A/C came on, there would be a loud click/knocking noise coming from the rear A/C located beneath the back side panel on the passengers side of the vehicle.) I was able to remove the plastic coverings and of course, I have the BEHR model, with the Actuators located behind the unit, against the body of the vehicle. I removed the two 7mm bolts that hold both the duct work and blower to the body. I then removed the duct and was able to apply a small amount of force and pull the blower mount slightly away from the body of the vehicle (I did not disconnect blower or clear any lines). At this point I disconnected the plug from the Actuator. To remove the Actuator, I used a Torx bit to remove the 3 screws mounting it to the blower housing. It was tight, but not at all impossible. The top 2 screws can be accessed from the top/left hand side of the unit, the 3rd screw (located on the bottom of the actuator), can be accessed much easier from the bottom near the wheel well where you can actually see the screw. Once I removed the actuator I was able to reconnect the plug and start the vehicle, testing the actuator further to ensure it was truly my problem. I also was able to visually inspect inside the blend door and verify that there was not a break causing the issue.

I hope this helps! I am by no means a "mechanic", simply a guy that doesn't want to pay $1,000.00 for a job that I can do at the house for free! This thread was essentially the only thing I found on the internet related to this model and situation, so thank you all for your help! I did take some photos/video and I will try and upload them as well.

Were you able to get the rear actuators out without removing the Freon? Also, how to you perform the calibration for these rear actuators on the 2016 Yukon?

I removed only one actuator and I didn’t have to mess with the Freon. The second actuator was directly beside it and it did not appear that you would need to mess with the Freon to replace it either.

Once you place the key in the ignition, the actuator cycles to self calibrate. When I initially reinstalled it, it wasn’t it the proper position. I was able to simply pull it back off and realign. Once I had it in place, I ran through all settings (A/C above and then to feet), I then tighten everything down and the job was complete. This was on a 2013 Chevroley Tahoe.

The rear HVAC is blowing hot when the AC is on. I had the dealership look at it and was told that the rear hvac temperature door actuator needed to be replaced. I ordered/received the new part and was able to remove the interior trim from the right/rear of the vehicle to access the rear hvac equipment. The actuator however is located BEHIND the hvac equipment. Pretty much between the blower/ductwork and the outside of the vehicle. My question is how do I pull the unit so I can access/replace the actuator??? Do I need to pull the heater lines, and if so, will I lose fluids, etc. and what add'l service will be needed.
Thank You.

your pic didnt' come through however try pulling fuse for that for a minute then reinstall with key on it may reset the actuator. see pics for removal air bags need to be disabled.

Excellent addition to this thread! Please feel free to use 2CarPros anytime!

I'm going to try to attach the photo again in this reply. The first thing I did was pull the fuse and try to reset the actuator but no luck. The diagrams you provided show how to pull the interior trim...I already got that off with no problem. The sticking point is accessing the actual actuator which is behind the HVAC unit. Hopefully the attached photo will come through and you can see what I mean. Thanks.

everything that I have in our manual is sowing the temp actuator in first pic and mode in 2nd pic, it says nothing about pulling the HVAC unit off the truck. i have checked 2010-2012 in both GMC and Chevrolet they both show the same setup. I have no further thing to tell you about this. Unless our manual is wrong. if you have to pull the HVAC unit you will have to blow the charge and evacuate and recharge entire system. it 's the same from 2009-2013.

Just rechecking your picture look at where the arrow is in this picture I put in. are you sure that is not the actuator?

Hi Guys, just wanted to let you know that i checked Alldata and got the exact same info that you did. It's on the outside.

Thanks for the responses guys.
I'm now I'm really stumped! I took a picture of the full unit and you will see that there are no actuators on the face of the HVAC unit like illustrated in the diagrams posted.
I placed the new actuator on top of the HVAC unit and took a picture (see my next post) shooting down from the top, behind the unit. You can barely see the installed/defective actuator and you will see that the shape and tab are the same as the new actuator so I'm pretty confident I'm looking at the right thing!!
Like I said...I'm stumped!! Anyone have a suggestion on how to proceed? I would hate to have to recharge the system..that's well out of my wheel house and I have no idea where I'd even begin.
Thanks again.

Got an issue where air not coming out of four roof vents. Research tends to indicate blend actuator and I have a buddy in parts that will sell it to me for his employee cost. Already got paneling remover but OMG, they are behind the HVAC unit. What in the world?

How in the heck are you supposed to do this?

other picture shooting down behind HVAC unit.

Welcome to 2CarPros.

Actually, the blend actuator is to determine temperature which enters the vehicle. I believe you have a problem with what is called a mode door actuator. That is what determines where the air flow exits.

Now, I don't know if you have automatic climate control or manual, so I am going to include directions for the mode valve actuator replacement for both. All attached pictures correlate with the directions.

_____________________________

Manual HVAC

See pics 1 and 2 for location and directions.

____________________________

Auto HVAC

See Pics 3 and 4 for location and directions.


____________________________

Here are the directions for recalibration of the automatic HVAC. You can do it with a scanner or without.

HVAC - AUTOMATIC
Actuator Recalibration

When replacing the HVAC control module it will be necessary to allow the HVAC control module to perform a calibration process. When installing the HVAC control module be sure to perform the following:

Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.


1. Place the ignition switch to the OFF position.
2. Disconnect the scan tool.
3. Install the HVAC control module.
4. Connect all previously disconnected components.
5. Start the vehicle.
6. Wait 40 seconds for the HVAC control module to self-calibrate.
7. Verify that no DTCs have set as current DTCs.

When replacing the HVAC actuator it will be necessary to allow the HVAC control module to perform a calibration process. When installing the HVAC actuator be sure to perform one of the following:

Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.


Preferred Method (w/Scan Tool)
1. Clear all DTCs.
2. Place the ignition switch in the OFF position.
3. Install the HVAC actuator.
4. Connect all previously disconnected components.
5. Start the vehicle.
6. With the scan tool, initiate the Motor Re-calibration feature of the Heating and Air Conditioning Special Functions menu.
7. Verify that no DTCs have set as current DTCs.

Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.


Alternate Method (w/o Scan Tool)
1. Clear all DTCs.
2. Place the ignition switch to the OFF position.
3. Install the HVAC actuator.
4. Connect all previously disconnected components.
5. Remove the HVAC/ECAS fuse for a minimum of 10 seconds.
6. Install the HVAC/ECAS fuse.
7. Start the vehicle.
8. Wait 40 seconds for the HVAC control module to self-calibrate.
9. Verify that no DTCs have set as current DTCs.

______________________________

Manual HVAC

HVAC - MANUAL
Actuator Recalibration

When replacing the HVAC control module it will be necessary to allow the HVAC control module to perform a calibration process. When installing the HVAC control module be sure to perform the following:

Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.


1. Place the ignition switch to the OFF position.
2. Disconnect the scan tool.
3. Install the HVAC control module.
4. Connect all previously disconnected components.
5. Start the vehicle.
6. Wait 40 seconds for the HVAC control module to self-calibrate.
7. Verify that no DTCs have set as current DTCs.

When replacing the HVAC actuator it will be necessary to allow the HVAC control module to perform a calibration process. When installing the HVAC actuator be sure to perform one of the following:

Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.


Preferred Method (w/ Scan Tool)
1. Clear all DTCs.
2. Place the ignition switch in the OFF position.
3. Install the HVAC actuator.
4. Connect all previously disconnected components.
5. Start the vehicle.
6. With the scan tool, initiate the Motor Re-calibration feature of the Heating and Air Conditioning Special Functions menu.
7. Verify that no DTCs have set as current DTCs.

Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.


Alternate Method (w/o Scan Tool)
1. Clear all DTCs.
2. Place the ignition switch to the OFF position.
3. Install the HVAC actuator.
4. Connect all previously disconnected components.
5. Remove the HVAC/ECAS fuse for a minimum of 10 seconds.
6. Install the HVAC/ECAS fuse.
7. Start the vehicle.
8. Wait 40 seconds for the HVAC control module to self-calibrate.
9. Verify that no DTCs have set as current DTCs.

______________________________
Let me know if this helps or if you have other questions.

Take care,
Joe

see if you can take out the bolts/screws of housing around blower and see if it will move enough to get to actuator screws they should be 7mm if memory serves me correct. or maybe take the clips off that duct work and if it will remove give you enough space to replace it with both things off and out of way.

Thank you for the reply. I believe you are correct in that it is the mode door actuator but fortunately it’s the same replacement part.

My issue (which is the same experience by user “jeff_wrenchonit” in this thread https://www.2carpros.com/questions/how-to-replace-rear-hvac-blend-door-actuator) is the pictures show the actuator attached to the front of the unit and thus easily accessible. Unfortunately that’s not where the ones on my truck are located. They are behind the unit (in the side of rear quarter panel). so when looking at the until normal you don’t even see them. Being that there is a screw that has to be removed and one essentially sits above the other, i have no idea how to get to it.

Just stumbled onto this thread with the help of Google. All the YouTube videos seem to be of the pre-2007 model, where the actuators are on front and nice and accessible. What a tease! As if pulling all the paneling apart wasn’t enough work, this is just ridiculous. I removed the 2 7mm screws from top but it certainly isn’t enough to get behind it. I’m thinking unit has to come off of sidewall somehow.

Any ideas? Videos, threads, suggestions? Thanks in advance! (I feel your pain, Jeff!)

Welcome back:

I have never had one like that. However, lets get through this together. I looked at the above link and identified the manufacturer. I had to use a different manual to even find it. Now, (and don't laugh) I had to put what they said are the directions in picture form. The first three is everything they provided. I have a feeling that you will laugh at them.

Next, I looked closely at the pic. I circled what I believe to be two screws at the top and at the bottom, I circled what I believe to be posts that are in rubber grommets. Once the screws are out, it looks like that would pull up.

Now to add insult to injury, this model also shows the mode actuator on the front. Since your's is different, make sure the pic looks like what you have. I noted that the vent to the ceiling is above the actuator in the pic.

Let me know if any of this helps. I wish I was there. It would be much easier. LOL

Take care,
Joe

GM used two different systems, apparently: the Delphi (which is the one where actuators are in the front) and Behr (you guessed it, in the back!). On the latter you have to disconnect lines, recover refrigerant, drain coolant, etc. I’ve attached pictures of the documents straight from the dealership service department.

Excellent addition to this thread! Are you asking for a short cut or? I would try to remove the torx bit and install it into a 1/4 drive socket with ratchet to see if you can get down there to get the screws out.

Did anybody figure out a short cut for this problem? I’m having the same issues. thanks in advance been very helpful so far. also, there’s 2 back there which one works what? any help would be grateful.

When I install the blend door actuator do I need to turn the temperature all the way up or down to get it to line up properly?

Good evening.

You need to align the motor with the blend door shaft. it will only go on one way. you may need to adjust the door to the motor shaft to get it in position.

After you get it bolted up, remove the fuse for the AC. wait about ten seconds. then install it and then turn the key to the on position. leave it there for about forty seconds that will calibrate the mode doors.

Roy

This guide shows which actuator does what:

https://www.2carpros.com/articles/replace-blend-door-motor

Please run down this guide and report back.

Okay, I will try in the morning and let you know, thank you.

The Berg unit has the actuators on top of each other in the back The one that’s bad on my mine works the hot and cold the one that’s good works the duck work is I’m assuming that’s the one on top because it’s closer to the duck work but I can’t tell for sure because I don’t have anyone here to work the controls. Are the actuators on the back both the same model. I can’t get any numbers off of it unless I take it off I do have the numbers off the front any help or input would be great. I would also like to thank everyone very much this has been more helpful then I could ever explain.

You are welcome.
Roy

They are indeed the same. Identical part numbers. Description is different (blend door actuator vs temperature door actuator) but same part number.

http://www.autogenius.info/chevrolet-tahoe-2009-2010-fuse-box-diagram/ this is a link to the fuse diagram for my 2009 Tahoe, could you please tell me which fuse I should remove? This is a huge help by the way. thank you!

Okay, thanks. will let everyone know if doable without unhooking everything.

Fuses 39 and 55 in the underhood fuse block will do it.

Roy

Please let us know if you need anything else to get the problem fixed. Use 2CarPros anytime, we are here to help. Please tell a friend.

Thank you, that is what I was thinking but was not sure. This is a great service. Thank you!

How will I know which actuator to change? My 2002 Chevy Tahoe blows heat out of front vents.

You are welcome, we are here to help.

Roy