Blend door actuator not working?

Tiny
A.JULIANW
  • MEMBER
  • 2005 CHEVROLET SILVERADO
  • 6.0L
  • V8
  • 2WD
  • AUTOMATIC
  • 165,000 MILES
I installed several new blend door actuators. They all do the same thing when I turn the ignition on. They spin and go to one side but don’t adjust when I turn the manual temperatures from hot to cold. I’m unsure what to do. I’ve read other post with testing voltage, and I’m stuck.
Saturday, April 22nd, 2023 AT 3:11 PM

24 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
Hi,

Do you have automatic or manual climate control? You should have dual climate control which indicates there should be two actuators. Does it happen on both sides of the vehicle?

Do me a favor. Try the relearn procedure listed below in pic 1. If that does nothing, we need to move on to testing.

As far as the issue is concerned, if I had your vehicle, I would start by scanning the can-bus system. This vehicle has several computers/modules that control different functions and determine if there are diagnostic trouble codes stored (other than powertrain), this needs to be done.

CAN stands for controller area network. As mentioned, there are multiple modules. Basically, the different modules are tied together via a few wires. This type of scan will retrieve codes regardless of the module storing them.

Here is a link that shows how it's done.

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Let me know what you find

Joe

See pic below.
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Sunday, April 23rd, 2023 AT 8:31 PM
Tiny
A.JULIANW
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Yes so, I do have a manual climate control. The issue is only with the driver's side temperature. The vent actuator is working properly and so is the passenger. The actuator I’m dealing with is underneath the glove compartment.
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Sunday, April 23rd, 2023 AT 8:35 PM
Tiny
JACOBANDNICKOLAS
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Hi,

If the left side isn't working, it should be further to the left of the glove box. The one for the passenger is on the right and behind the glove box.

Take a look at the attached pic and let me know if that is the one you are working with.

Let me know.

Joe

See pic below.
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Monday, April 24th, 2023 AT 6:12 PM
Tiny
A.JULIANW
  • MEMBER
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Yes so, it’s the one on the left side under the glove box. I’ve already had the wire pulled exposed. I hooked up a new actuator or rotates once and it doesn’t move when I manually adjust the temperature.
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Monday, April 24th, 2023 AT 6:15 PM
Tiny
JACOBANDNICKOLAS
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Hi,

Did you try the manual reset I attached above?

Joe
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Monday, April 24th, 2023 AT 7:07 PM
Tiny
A.JULIANW
  • MEMBER
  • 13 POSTS
I will try hopefully later today. The truck is in the shop for other issues at the moment.
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Tuesday, April 25th, 2023 AT 5:33 AM
Tiny
JACOBANDNICKOLAS
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Hi,

Sounds good. Let me know how things turn out for you.

Take care,

Joe
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Tuesday, April 25th, 2023 AT 6:34 PM
Tiny
A.JULIANW
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Good afternoon, I just got the truck back today. After just looking at the module I noticed this wire. Could this be the reason I’m having the issue?
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Monday, May 8th, 2023 AT 12:57 PM
Tiny
JACOBANDNICKOLAS
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Hi,

Interestingly, the white wire with a black tracer controls the passenger side (right side). See pic below.

However, if that wire is damaged, there are likely others. Check for a dark blue wire. See if there is damage. Also, there will be a light blue wire with a black tracer. That provides the 5v reference. Locate that and see if there is power. Also, there should be a brown wire that provides battery voltage. Check that as well. It comes from the HVAC 1 fuse in the interior fuse box.

Let me know.

Joe

See pic below.
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Monday, May 8th, 2023 AT 7:14 PM
Tiny
A.JULIANW
  • MEMBER
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So, I’ve checked the voltage from the module to the pin (actuator hookup) and I’m getting power.
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Monday, May 8th, 2023 AT 7:23 PM
Tiny
JACOBANDNICKOLAS
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Are you getting the reference voltage via the light blue wire/light blue wire with a black tracer when changing the temp request?

Joe
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Monday, May 8th, 2023 AT 8:35 PM
Tiny
A.JULIANW
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I’m sorry what is the reference voltage?
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Monday, May 8th, 2023 AT 9:04 PM
Tiny
JACOBANDNICKOLAS
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Hi,

No problem whatsoever. It should be a 5v reference.

Joe
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Monday, May 8th, 2023 AT 9:14 PM
Tiny
A.JULIANW
  • MEMBER
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I just checked the voltage changing the temperature to hot I get 4.90. Then cold 4.90 and this was for the light blue wire with black in the middle.
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Tuesday, May 9th, 2023 AT 2:51 PM
Tiny
JACOBANDNICKOLAS
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Hi,

That couldn't be closer to perfect. If we have the power where it is needed and the actuator isn't reacting properly, I would say you got a bad actuator, but you have replaced them several times.

Question, when you found the voltage, did the 4.9v show positive voltage at the same wire when you changed temps?

Joe
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Tuesday, May 9th, 2023 AT 7:57 PM
Tiny
A.JULIANW
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Yes, the voltage was the same when I changed from hot to cold, and vice versa.
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Wednesday, May 10th, 2023 AT 2:52 AM
Tiny
JACOBANDNICKOLAS
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Hi,

When the motor needs to turn in the opposite direction, the polarity needs to change direction. In other words, it has to travel in the opposite direction for the motor to turn in the opposite direction.

Also, does the voltage change as you move through the temperature slowly? If it doesn't, chances are the controller has an internal fault.

Let me know.

Joe
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Wednesday, May 10th, 2023 AT 7:39 PM
Tiny
A.JULIANW
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So, I checked the voltage from hot to cold slowly and the voltage did not change. Does that mean the module is bad?
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Thursday, May 11th, 2023 AT 3:07 PM
Tiny
A.JULIANW
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Also, I know noticed that When I change the fan speed 1-3 work (4 stops) and 5 works. This just started today.
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Thursday, May 11th, 2023 AT 3:58 PM
Tiny
JACOBANDNICKOLAS
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Hi,

That would be my first suspect since there is no change at the actuator. As far as the speeds are concerned, it is controlled by a blower motor resistor. However, if it is the module, that could be another symptom.

Let me know.

Joe
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Friday, May 12th, 2023 AT 6:23 PM

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