Heating and A/C blend door not working properly

RONALD LEE SMITH

MEMBER
1993 CHEVROLET SILVERADO
5.0L
V8
2WD
AUTOMATIC
104,000 MILES

Blend door on heat/AC will only turn one way! I put on new actuator Because large gear was cracked! Are there any climate control things on the truck listed above that I need to calibrate, if so, how is this done! Thank you!

Wednesday, February 9th, 2022 AT 2:31 PM

9 Replies

KASEKENNY

MECHANIC
18,907 POSTS

There is no calibration on this door but there is an adjustment process.

I am attaching the process below.

Also, here is a guide that will help with replacement, but I don't think that is your issue, but it is still good info:

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

What I would suggest is remove the actuator and turn the ignition on. Then move the temperature to full hot or full cold.

Then manually move the door with your finger to this position and install the actuator. This way you know for sure that it is set to full hot or cold.

Then adjust the temperature and if it does the same thing then we need to run through the testing on the last attachment below.

Basically, this is going to tell us if we have a controller issue or a possible wiring issue.

Let me know what questions you have.

Thanks

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Thursday, February 10th, 2022 AT 4:29 PM

RONALD LEE SMITH

MEMBER
5 POSTS

Thank you, Kenny K.

The motor on the new Actuator will only run in one direction. My actuator has 5 pins 5.6. (No 7) then 8.9.10. Watched a video and it said to make it turn in other direction jump 6 and 7 and motor will reverse but mine won’t (I don’t have a 7 pin) in other direction at all no matter what pin I jump. Using ohm meter, and voltmeter. I tried to test the control module, the defrost, to floor and vent, works fine, the A/C turns on, but could not get any change when going to hot or cold. It all started when gear broke on the actuator! Or maybe I’m not getting the right Actuator, because the ones I have doesn’t have a 7 pin!
Thank you again!

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Thursday, February 10th, 2022 AT 5:55 PM

KASEKENNY

MECHANIC
18,907 POSTS

You are correct. More than likely the one they had was a different system.

You have 5 pins and I listed them below.

Looks like you need to jump 705 to 1644 for one direction and the other is 1645 for the other direction.

This would be 10 to 5 and then 6.

However, what I would do instead of jumping them, I would check the voltage on pin 5 and 6 when moving in each direction.

It sounds like the controller is not commanding the reverse direction. So, if there is no voltage then we need to ohm out the wiring and make sure it is not a wire issue.

Here is a guide that will help with this:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Let us know what you find.

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