Novak Conversions Jeep Wrangler JK shifters

How to replace the A/C blend door on your Jeep Wrangler JK

Chris

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A/C blend door actuator in your Jeep JK is a very important part of the heating and cooling system and is responsible for controlling the temperature of the air blowing thru the vents and into the cabin. To blow heat into the cabin, the blower motor sends air through the heater core and on through the dash vents. But when heat is not desired, the blend door actuator directs that airflow away from the heater core. Unfortunately blend door actuators can fail at some point and cause the inability to change the air temperature inside your Jeep. The reason I needed to replace the blend door actuator in my Jeep was due to the horrible and loud ticking/grinding noise that it was making every time I put the key in the ignition. I also noticed that the actuator resets itself and makes the same noise after about two minutes from turning off the engine. With the Jeep being topless and doorless, and me using public parking lots, I was afraid someone walking by would freak out and call the cops, thinking my Jeep was about to explode.

You might also experience this loud ticking noise when you open your door, turn on the ignition, or turn the temperature knob on the HVAC control panel. You might also simply not have any hot air coming to the cabin, which means that your blend door actuator is not working at all, and needs replacing.

Here are a couple of videos showcasing the noise being emitted by the broken blend door actuator: video 1 and video 2. I also used these videos in the process of creating this step-by-step write up. Thank you to the authors of the videos!

I could be wrong, but I believe there are actually three actuators installed in a Jeep Wrangler JK, each responsible for different function. There is the blend door actuator responsible for controlling the temperature, the directional actuator (probably not a correct technical name) responsible for directing the air to different vents, and the re-circulation door actuator which controls the air dam behind the glove box.

Each actuator is activated by a different knob or setting on the HVAC control panel.

If you run your Jeep for few minutes, take the glove box out, and turn off the engine, after about two minutes you can see and hear three small motors re-calibrating the three actuators, in sequence.

I do believe all three actuators are the same exact part even though they are mounted in different locations. Blend door actuator is located on the driver side below the steering column, directional actuator is located behind the glove box on the left side, and the re-circulation door actuator is located on the right side of the air dam, behind the right speaker.

This step-by-step write up describes replacement of the blend door actuator only, since that’s the one that failed in my case. As a reference I included a photo of the directional actuator in the last picture.

I have a 2012 Jeep JK so if you own a different Model Year JK, some things might look different.

Replacing the blend door actuator itself is quite simple, however getting access to it is the time consuming part.

The whole process of a Jeep JK A/C blend door actuator replacement will most likely take you about 2-3 hours, depending on few factors, especially on how long it takes you to remove the floor air duct, blocking access to the actuator. That step might take you few minutes or an hour.


Disclaimer:
Like I always mention I am not a professional mechanic, I just try to do as much work on my Jeep as possible. It helps me learn more about my vehicle and save some money that can be spent on parts and upgrades.
I take no responsibility for any injury or breakage which might occur if you decide to follow these steps. You have to decide if you’re comfortable working on your Jeep. If you’re not, please have a professional complete this project for you.



Parts and tools needed:

1. Jeep JK A/C Blend Door Actuator by MOPAR, or Dorman A/C Heater Blend Door Actuator
2. 3/8″ Ratchet and 8mm & 10mm sockets
3. 10″ Long 3/8″ Drive Extension Bar
4. 8mm Combination Wrench
5. Stubby Phillips Screwdriver
6. 45-Degree Bent Long Nose Pliers


Procedure:

Step 1:

Prepare your tools and get everything ready before you start the project.

Jeep_JK_Blend_Door_Actuator_0001.jpg




Step 2:
Disconnect negative terminal of your battery. This is an optional step, however you are going to be disconnecting and reconnecting electrical connectors inside your Jeep during this project.

Jeep_JK_Blend_Door_Actuator_002.jpg




Step 3:
The driver side A/C blend door actuator is located inside your Jeep’s dashboard, below your steering wheel. Removing your driver side door completely will help you with access to the components you’re going to be working on.

Jeep_JK_Blend_Door_Actuator_003.jpg




Step 4:
Remove the plastic panel below your steering wheel. It is held in place by four clips. Start from the top and pop it off. It will tilt downward on the two plastic hinges at the bottom. Put the entire panel to the side.

Jeep_JK_Blend_Door_Actuator_004.jpg




Step 5:
Remove the metal plate by unscrewing two 10mm bolts.

Jeep_JK_Blend_Door_Actuator_005.jpg




Step 6:
Removing the metal brace on the right side will provide better access to other components. Remove the top bolt using an 8mm socket.

Jeep_JK_Blend_Door_Actuator_006.jpg




Step 7:
Remove the bottom bolt with an 8mm wrench.

Jeep_JK_Blend_Door_Actuator_007.jpg




Step 8:
Unscrew two bolts securing the control box, using an 8mm socket with 10″ extension. No need to unplug the box, however you will need to pull it away from the Jeep’s body and twist it, in order to move it away from the actuator and gain better access to it.

Jeep_JK_Blend_Door_Actuator_008.jpg




Step 9:
Now comes the most frustrating part
For total access to the blend door actuator, it’s arm and the track, you will need to remove the air conditioning floor duct. The duct is made out of two plastic pieces, held together with seven tabs. Separating the two halves and pulling them out is going to be the most time consuming and irritating part of the entire project. Take your time and be patient. What I found to work best is to squeeze the outer shell of the duct in the middle with one hand, and with your other hand place your finger between the two halves right at the top. Carefully but forcefully run your finger along the edge of the duct and you should be able to feel the outer shell separating. As soon as you get more leverage, the process should become easier. Be mindful of all the wires in the area. When you finally get the outer half of the duct free, pull it out thru the bottom of the footwell.

Jeep_JK_Blend_Door_Actuator_009.jpg




Step 10:
With the outer portion of your Jeep’s floor duct gone, it’s time to remove the inner half. It is not held in place with any screws, it is only attached at the top by being pushed into an opening in the distribution housing. The duct is held there with a couple of tabs. I found that simultaneously twisting the duct upwards and towards the front of the Jeep, helped with the removal. It is a slow process as the duct seems to come out just a bit at a time. Again, be patient and take your time. As soon as you get it loose, simply pull it out thru the bottom of the footwell. Pay attention to the way it’s coming out, so you can reverse the process later on.

Jeep_JK_Blend_Door_Actuator_010.jpg




Better view of your Jeep JK driver side floor duct assembly.

Jeep_JK_Blend_Door_Actuator_012.jpg




Floor duct’s two halves with the tabs holding them together.

Jeep_JK_Blend_Door_Actuator_013.jpg




Closeup of the edge and one of the tabs.

Jeep_JK_Blend_Door_Actuator_014.jpg




Upper portion of the inner shell of the duct, with the holes and bend/tab holding it secured to the dashboard.

Jeep_JK_Blend_Door_Actuator_015.jpg




Step 11:
With the air duct gone, you now have full access to the actuator and the track that it connects to. Before you remove the actuator, unplug it’s electrical connector. You can also unplug the accelerator pedal connector, for better access to the two screws securing the actuator in place. Carefully remove the two screws with a stubby Phillips screwdriver, making sure you don’t strip or drop them. Pull out the blend door actuator, with the arm attached.

Jeep_JK_Blend_Door_Actuator_011.jpg




Step 12:
You can open up the actuator if you want to inspect the mechanism inside, and the damage causing it to not work properly.

Jeep_JK_Blend_Door_Actuator_016.jpg




The most common reason for the actuator to fail is a broken gear tooth. These gears are made of plastic and brake without warning. It would be nice if these gears were metal, however I don’t believe that’s even an option on brand new replacement actuators.

Jeep_JK_Blend_Door_Actuator_017.jpg




Step 13:
Carefully remove the plastic arm attached to the old actuator and transfer it to the new one. Try attaching it at a similar angle.

Jeep_JK_Blend_Door_Actuator_018.jpg




Step 14:
Install your new blend door actuator. Position the pin of the arm inside the track, position the body of the actuator in place, and secure with the two screws. I found it helpful to use the 45-Degree bent long nose pliers to hold the screw with one hand and operate the stubby screwdriver with the other hand. Plug in the electrical connectors of the actuator and accelerator pedal. If you wish you can reconnect your battery now, to test your new actuator, otherwise reconnecting the battery can be your last step. If everything seems to work correctly, start carefully installing the air duct back in place. Make sure no wires get in the way while you snap the two halves of the duct together. Secure the control box back in it’s location, install the metal brace and the plate, and finally push-in the plastic panel under your steering wheel.



UPDATE: About a week after installing the Dorman blend door actuator I actually ended up replacing it with the MOPAR version. Right after the Dorman actuator was first installed I started having an issue with the defrost light on the control panel blinking for approximately 30 seconds every time I started my Jeep. Only after the indicator stopped blinking, the air would begin to come out of the vents. The actuator would also randomly make whining noises. It is possible that I received a defective part. I ended up returning it and bought the MOPAR actuator, which I installed the same way. I have not had any issues since.

Jeep_JK_Blend_Door_Actuator_019.jpg




As a reference, here is a picture of the “directional” actuator, located behind the glove box, on the left side and mounted to the center console. The recirculation door actuator is located on the right side of the air dam, behind the right speaker, and not visible without removing the speaker box.

Jeep_JK_Blend_Door_Actuator_020.jpg
 
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Just an FYI....2010 does not have actuators for the blend door or the direction. It only has one for the recirculation. The other 2 are cable actuated.
Not sure if they changed to all actuators in 2011 or 2012.
 
This post is old, but one of the more valuable posts relating to replacing the blend door. I replaced mine on a 2014 JK this morning in little more than an hour. Here are some tips you may find helpful.
I bought a cheap Dorman replacement motor.
I used a 1/4 drive ratchet wrench, sockets, and extensions because they're plenty strong and smaller is better for this job. I didn't have any need for pliers, magnets, or mirrors but a good light is imperative.
Some "how to" videos don't recommend removing the brace like this post does. It's important. A "gearwrench" style ratcheting wrench is very helpful for removing/installing the lower bolt which is WAY longer than necessary. There isn't much room to swing a wrench and a ratchet type will save time.
Removing the gas pedal wiring helps give more room.
I took out the ducting in one piece by simply pulling it to the left and wiggling it out. It went back together in one piece too. It was easy and I didn't have to depress any tabs or pry on anything Just a firm jerk to the left and out it comes. People report fiddling for an hour with this duct, but mine took one minute out and 90 seconds to get it in.
I put a short shop stool just outside the door and used it to sit on for about 2/3 of the job. It will save your back some pain.
I used a regular length Philips screwdriver rather than a stubby and I think it was a better choice.
Put your new motor and old motor on a bench oriented the same way. When you remove the actuator arm from the old one, note carefully how the arm is oriented relative to the motor shaft. The shaft has one missing tooth but the arm doesn't; consequently the arm can go on in about 8 or 10 different WRONG positions. The missing tooth on my old motor was about 45 degrees different from the new motor and I couldn't turn either shaft without risking breaking something. So I installed the arm in the new motor so that it was also 45 degrees different. In other words, I made the arm match the position of the missing tooth, but you have to pay close attention when you remove the arm from the old motor since there is no reference on the arm. A smart DIY mechanic might use a marker to draw a line on the arm corresponding to the missing tooth on the motor shaft. I imagine the orientation of the old motor shaft depends on where it was when it died or perhaps where it was when the old gears stripped. In any case, your job is to install the arm on the new motor so that is in the same relationship to the missing tooth on the shaft even if the old and new shafts are in different positions.
Putting everything back together was easy. After getting the motor mounted and plugged in, I connected the battery and tested the heater so that I could watch it operate from hot to cold and back again. Previously my environmental control panel did that yellow blinking light routine every time I started the jeep in an attempt to calibrate the failed blend door motor. Now it doesn't do that, it doesn't make any funny noises, and the heater blows hot air.
The repair took me just over a hour, but it was cold outside today and arthritis makes my hands not as nimble as they once were. I'm 80 years old and this job was well within what is left of my capabilities. I didn't suffer any of the normal cuts and bruises either. I'd rate this job as pretty easy, thanks in part to the instructions and excellent photos posted by the OP.
 
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Novak Conversions Jeep Wrangler JK shifters