Hey, I broke the plastic shaft that controls the actuator as well. have you had any luck repairing it?
Jun 13, 2019 at 12:41 PM
Blend door actuator
2004 GMC YUKON
CASSON
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Hi Casson,
Unfortunately, there is no real way to repair these shafts or the gears. The doors are actually put under a significant amount of stress when they are opened and closed and they reach their stopping point. Unless you actually replace the shaft they will just break during these high points of stress. Unfortunately, I do not know where you can get the parts to rebuild them. Plus they are cheap enough these days, that we just replace them.
Let me know if you have other questions. Thanks
Unfortunately, there is no real way to repair these shafts or the gears. The doors are actually put under a significant amount of stress when they are opened and closed and they reach their stopping point. Unless you actually replace the shaft they will just break during these high points of stress. Unfortunately, I do not know where you can get the parts to rebuild them. Plus they are cheap enough these days, that we just replace them.
Let me know if you have other questions. Thanks
Jun 13, 2019 at 2:25 PM
Well I glued the shaft back on and installed a new actuator. Then I noticed the 10amp HVAC fuse was blown so I replaced it. My controls for defrost/floor/front vent worked for about ten minutes then I heard the new fuse pop. now it’s stuck on floor setting and still blowing out heat all the time. any advice on where to go from here would be greatly appreciated. Thanks.
Jun 14, 2019 at 10:32 PM
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Okay. So we have two issues. One is the direction of the air and the other is the temperature. They could both be actuators because they are controlled by different actuators.
The air temperature is controlled by a blend door/air temp door and the direction is controlled by a mode door.
Let's address the mode or position first, As you will see in the attached documents, the actuator is controlled by the HVAC control module to move positions. If it is stuck on one setting then it is either the actuator or the module. Since this was already broken, I would suspect the actuator is the issue.
As for the temperature only blowing warm, we need to make sure the actuator is moving when you are commanding cold air. If not, then that will need to be replaced.
Here is a video on how to replace this on a GM:
https://youtu.be/tY6M92fA2ug
If it is moving then we need to look to see if the compressor is coming on. Was the AC operating properly before the mode door actuator broke?
If so, I would address that issue and then retest operation. Keep me posted with what you find.
The air temperature is controlled by a blend door/air temp door and the direction is controlled by a mode door.
Let's address the mode or position first, As you will see in the attached documents, the actuator is controlled by the HVAC control module to move positions. If it is stuck on one setting then it is either the actuator or the module. Since this was already broken, I would suspect the actuator is the issue.
As for the temperature only blowing warm, we need to make sure the actuator is moving when you are commanding cold air. If not, then that will need to be replaced.
Here is a video on how to replace this on a GM:
https://youtu.be/tY6M92fA2ug
If it is moving then we need to look to see if the compressor is coming on. Was the AC operating properly before the mode door actuator broke?
If so, I would address that issue and then retest operation. Keep me posted with what you find.
Images (Click to enlarge)
Jun 16, 2019 at 8:31 AM
Does the blend door actuator in the video control both temperature of the air and direction it blows out? I have the control module off with the blend door unplugged and the blower resistor motor off and the fuse still pops.. I can tell the blend door has changed position because it’s not in the middle anymore.
Jun 16, 2019 at 12:43 PM
The blend door does not appear to be moving when I adjust the temperature. The fuse pops even before the truck is started if that helps at all...
Jun 16, 2019 at 6:02 PM
Okay. If the fuse is blowing then that means there is too much current on the circuit.
This is pretty involved wiring diagnosis but the short of it is you need to identify what is on that fuse and test it for being shorted. Then you need to test the wiring from the fuse to the component or load and see if you have shorted wire.
Here is a guide that walks you through the basics. Have you ever done this type of diagnosis? If so, test the wiring for short to ground, power, and shorted to other circuits. If not, we can try to walk through it but you will need a volt meter and tell me what fuse is blowing.
https://www.2carpros.com/articles/how-to-check-wiring
This is pretty involved wiring diagnosis but the short of it is you need to identify what is on that fuse and test it for being shorted. Then you need to test the wiring from the fuse to the component or load and see if you have shorted wire.
Here is a guide that walks you through the basics. Have you ever done this type of diagnosis? If so, test the wiring for short to ground, power, and shorted to other circuits. If not, we can try to walk through it but you will need a volt meter and tell me what fuse is blowing.
https://www.2carpros.com/articles/how-to-check-wiring
Jun 17, 2019 at 1:11 PM