The HVAC temperature will not switch from hot to cold and back why?

Tiny
JOHNNYO70
  • MEMBER
  • 2010 CHEVROLET SILVERADO
  • 1.7L
  • V8
  • 4WD
  • AUTOMATIC
  • 110,000 MILES
My climate control works but doesn't throw heat or A/C mechanic said it's the blender on the top of the dashboard or the wiring which it was messed with. Need help finding this pin out please.
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Friday, June 26th, 2020 AT 5:41 AM

31 Replies

Tiny
ASEMASTER6371
  • EXPERT
Good morning,

The actuator is the most common failure for the temperatures not changing. It is on top of the heater case as your tech stated. This guide and video will show you how to change it.

https://youtu.be/Eqf-H3COtSo

and

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

I attached the pinout of the module as you requested.

https://www.2carpros.com/articles/how-to-check-wiring

I also attached the actuator replacement procedure and location of the blend door for you. Check out the diagrams (Below). Let us know what happens and please upload pictures or videos of the problem.
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Thursday, August 27th, 2020 AT 10:01 AM
Tiny
BRYAN42
  • MEMBER
  • 2010 CHEVROLET SILVERADO
  • 4.8L
  • V8
  • 2WD
  • AUTOMATIC
  • 176,000 MILES
Truck blows hot air no matter what setting it is on. The system is full of Freon. Compressor goes on and off along with the condenser cooling fans operating normally. I've noticed the high pressure side where the orifice tube is located icing over going in towards the firewall. Also, before the start of all this, there was a popping noise coming from under the dash towards the floor board on the passenger side. I've also noticed that once the popping stopped, that is when it started blowing hot. The blend door seems to be operating correctly, but not exactly sure where the temp control actuator is located on this particular model. Any help on this would be much appreciated. Thanks!
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Friday, April 30th, 2021 AT 2:05 PM (Merged)
Tiny
SCGRANTURISMO
  • EXPERT
Hello,

This definitely sounds like it could be a problem with your Heating Ventilation Air Conditioning (HVAC) blend door actuator. I have included diagrams down below in the diagrams down below of the location of the blend door actuator for your vehicle. I also have included a link for you to go to:

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

Please go through the guides and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros
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Friday, April 30th, 2021 AT 2:05 PM (Merged)
Tiny
BRYAN42
  • MEMBER
Is Fig. 2 for a dual climate control and Fig. 3 for a single? Just want to make sure im reading this right because I have a single control unit and not a dual.
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Friday, April 30th, 2021 AT 2:05 PM (Merged)
Tiny
SCGRANTURISMO
  • EXPERT
Hello again,

Figure 2 is Auto Climate Control and Figure 3 is for Electronic Control. The way I see it is Figure two is when you set a desired temperature and the vehicle maintains that cabin temperature for you, and figure 3 is for you have to manually adjust the temperature yourself. It must be an option on your vehicle.

Thanks,
Alex
2CarPros
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Friday, April 30th, 2021 AT 2:05 PM (Merged)
Tiny
CHRISBUCKMAN1500
  • MEMBER
  • 2009 CHEVROLET SILVERADO
  • 4.3L
  • V6
  • 2WD
  • AUTOMATIC
  • 57,000 MILES
I have discovered that the heat/cool blend actuator is not always working and that I may need to replace it but I do not know where it is located, when I took the (3) 7 mm screws from under the dash near the floor, then removed the cover I did not see any actuators just more plastic, so before I start pull the whole thing apart or paying some crazy amount of money I was wondering if you knew where it is located or even have the exact diagram for my truck? Thanks.
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Friday, April 30th, 2021 AT 2:05 PM (Merged)
Tiny
KEN L
  • ADMIN
Hello,

Here is a guide to help you see where all blend door motors are with diagrams below

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

Try pulling hvac fuse under hood for 60 seconds first as it may reset the actuators. see pic for temp actuator, if you have both left and right temps this is also for right side. Check out the diagrams (Below) Please let us know if you need anything else to get the problem fixed.
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Friday, April 30th, 2021 AT 2:05 PM (Merged)
Tiny
CRICH8136
  • MEMBER
  • 2005 CHEVROLET SILVERADO
  • 200,000 MILES
The driver side vents would flip from AC to very hot air. I watched the video and replaced the blend door actuator. Did the re-calibration by disconnecting the battery for about fifteen minutes, reconnect and turn the truck on for one minute. Turn off a few minutes and turn on again two minutes. I could hear a ratchet sound during the process. Now it is hot all the time and very little air volume coming from the passenger side vents. What can I do to fix this? Thanks.
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Friday, April 30th, 2021 AT 2:06 PM (Merged)
Tiny
CRICH8136
  • MEMBER
Looking at your diagrams, it appears I replaced the wrong actuator. The one I replace is shown in your photo below under the cowl on the passenger side. Is the correct one under the top of the dash? Do you have a video showing how to get to it?
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Friday, April 30th, 2021 AT 2:06 PM (Merged)
Tiny
ASEMASTER6371
  • EXPERT
That is correct. That is not the actuator. The correct one is under the dash, left side above the fuel pedal.

I attached a picture and the procedure. Easy replacement.

Roy

REMOVAL PROCEDURE
1. Remove the I/P insulator panel.

ImageZoom/Print

2. Disconnect the electrical connector (1) from the left air temperature actuator (2).
3. Remove the screws from the left air temperature actuator (2).
4. Remove the left air temperature actuator (2) from the HVAC module assembly (3).
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Friday, April 30th, 2021 AT 2:06 PM (Merged)
Tiny
CRICH8136
  • MEMBER
Now I am confused. According to what I have read, the actuator on the left over the gas pedal is the mode door. Most of the videos I have seen state that the hot/cold on the driver side is regulated by the actuator on the right side underneath, the one I replaced. I even think the 2CarPros video stated or implied that. But the diagram on the 2CarPros article suggested that the driver side hot/cold was the actuator on the top right side (not the recirculate). So I am thinking that I did replace the correct actuator, but that either my replacement part is not correct or I did the re-calibration wrong.
I opened the actuator that I took out. It did not have the metal under the large gear, nor the track on the board like all the ones in the videos have. I do not know what that could mean. Outside, the actuators look the same.
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Friday, April 30th, 2021 AT 2:06 PM (Merged)
Tiny
ASEMASTER6371
  • EXPERT
If you have dual control or left and right control, that is the left side.

If you have only one control for both sides then it is the one on the right side.

Since you said only the left side goes warm, it sounds like you have dual control.

Roy
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Friday, April 30th, 2021 AT 2:06 PM (Merged)
Tiny
CRICH8136
  • MEMBER
I installed the actuator and did the calibration. The air was coming out hot but not as hot as sometimes which means that the door was in the half open position just the way the actuator was installed.
I looked at the plug and found two rows of contact holes. The bottom row has the metal contacts. My plug is going into the top row (based on how close the pins are to the edge of the housing). There appears to be some metal in the top row. Will it work to plug it into either row?
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Friday, April 30th, 2021 AT 2:06 PM (Merged)
Tiny
JSAWHITE2
  • MEMBER
  • 2004 CHEVROLET SILVERADO
  • 5.3L
  • V8
  • 2WD
  • AUTOMATIC
  • 90,000 MILES
I watched you video on replacing the blend door actuator. I successfully removed the old, and installed the new. It was still blowing hot, out of the driver's side. It seems like the actuator is being told, to turn the shaft, to heat. I removed the new one, and tried seeing if the actuator would move, when adjusting temp. Kind of at my wits end, on this one. Any advice, would be appreciated.
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Friday, April 30th, 2021 AT 2:06 PM (Merged)
Tiny
HMAC300
  • EXPERT
Here is the video

https://youtu.be/Eqf-H3COtSo

you can try tip that I'm sending also try removing hvac fuse inside truck for 60 seconds then reinstall. Do not move any hvac controls after reinstall. wait another minute and see if it straightens out. then look at first pic that is a tip that other mechanics have found.

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

Check out the diagrams (Below). Please let us know what you find. We are interested to see what it is.
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Friday, April 30th, 2021 AT 2:06 PM (Merged)
Tiny
ASEMASTER6371
  • EXPERT
The plug only goes on one way.

Are you sure you have the correct actuator?

Roy
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Friday, April 30th, 2021 AT 2:06 PM (Merged)
Tiny
CRICH8136
  • MEMBER
After I wrote above I looked at my old actuator. Its pin placement is identical to the new one. I can only assume that there are contacts in both holes. The 2 / 3 pin lineup is correct. And, as you said, the plug only goes in one way.
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Friday, April 30th, 2021 AT 2:06 PM (Merged)
Tiny
1BIGFISH
  • MEMBER
  • 2004 CHEVROLET SILVERADO
  • 5.3L
  • V8
  • 2WD
  • AUTOMATIC
  • 179,000 MILES
I have the manual temp control and I know my actuators do not work. I have replaced the actuator located at the bottom over the transmission tunnel. It moves with the temperature control. I still cannot move the air off the defrost and don't think I get recirculating air. So, here is my question. Per your diagrams, it looks like there are a total of four actuators. When I look for the part, I find it confusing to find the correct part number for each actuator even though I have the RPO codes. I installed Dorman 604-112 and it works great. Is it possible that this same actuator will work in all four spots?
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Friday, April 30th, 2021 AT 2:06 PM (Merged)
Tiny
STEVE W.
  • EXPERT
It is rare for all of the actuators to fail at once. In your case it sounds like the mode actuator on the left side (drivers side) at the top of the case has failed. It controls the floor/dash/defrost modes. I believe you can change it without taking the entire dash out.

In the picture six is the mode door actuator, two is the re-circulation door actuator, four is the passenger side blend door actuator and the one you replaced is the drivers side blend door unit. Depending on the actual option package and controls the actuators are the same for the two blend doors, the mode unit is different as is the re-circulation actuator.

Here is a guide that can help you too.

https://www.2carpros.com/articles/replace-blend-door-motor
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Friday, April 30th, 2021 AT 2:06 PM (Merged)
Tiny
1BIGFISH
  • MEMBER
I appreciate you providing some light on this topic for me. Donation sent! Thanks.
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Friday, April 30th, 2021 AT 2:06 PM (Merged)

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