HVAC problems - blend door?

[EvilZL1]

I have the blend door issue now, I'm not looking forward to repairing/replacing the door since all the dash has to come out. But I will need A/C and heat here

[silverstorm]

Originally Posted by EvilZL1

I have the blend door issue now, I'm not looking forward to repairing/replacing the door since all the dash has to come out. But I will need A/C and heat here

If you do this on your own, I just might pay you to help me out since I don't trust the dealership or paying $1500+ for the job. I've had the problem since like October

[Redvert12]

I just had this problem and had the local dealer repair it. I'm all about DIY, but when I saw the windshield had to come out also, I don't have room for all of theat.
The bill was $1275 but did not include windshield. Luckily I had some chips that were in my line of sight so the insurance company replaced the windshield. $100 deductible and I demanded OEM windshield due to HUD. The windshield wasn't broken while removing but< as mentioned before, the seals were damaged while removing it. They only come on new windshield.
Like it has also been mentioned< thanks Chevy for such an engineering nightmare. I expect I will be selling in a year or two to avoid this nightmare again,

[Rem0v3r]

Mines broken also.. there is a few videos online, you can cut the box open without removing the dash.. if you're handy.

[DADs'_SS]

Hi guys,

Ive done the repair myself for less than 100$!!

Here is a how to I have parts 1-5 on youtube. Feel free to ask me any questions.

https://youtu.be/KBV4cNpX8Rw

[gringo]

Is there a way to keep this from breaking prematurely?

You know like not turning the temperture knob dial too many times to save wear and tear on the bend door mount from breaking?

I rarely use the heat function. So, I keep it mostly on the coldest setting (blue dot) part of the dash panel.

[polizzio]

Originally Posted by gringo

Is there a way to keep this from breaking prematurely?

You know like not turning the temperture knob dial too many times to save wear and tear on the bend door mount from breaking?

I rarely use the heat function. So, I keep it mostly on the coldest setting (blue dot) part of the dash panel.

I had/have the same questions in my mind after viewing the recent pics another member posted doing this job. What causes the failure, and what can I do as an owner to reduce the possibility of it occurring?

I might just start wearing a coat and hat in cold weather while using my car. Must have been a faulty design, or a weak plastic casting of the blend door.
Must really suck when it fails. Guys say its hot all the time, even with the AC on. What a freakin nightmare! $1500+ repair at the stealer.

[152LTRockin]

Just so you all know the REAL issue with the door breaking is because the actuator fails and does not stop but continues to force against the blend door until it breaks the door. The most likely preventive thing to do is replace the actuator before it fails internally and won't stop. I'm sure there is some type of feedback circuit built into the actuator to confirm its position.

As soon as I get time I'm going to pull a actuator apart and do some testing to see why they fail so much. If anyone has the factory manual with electrical schematics and other HVAC info would be a great help as I don't have the factory manuals.

I will find a solution and post it, if anyone has a broken blend door I'd like to have the old actuator to diagnose the problem and come up with a fix for everyone that's permanent. GM is never going to step up and fix the actuators, I believe they were designed to fail as crazy as it sounds. Gotta make work for their dealers.

It maybe as simple as limiting the amount of torque the actuator can apply if the feedback circuit fails.

[gringo]

Originally Posted by polizzio

I had/have the same questions in my mind after viewing the recent pics another member posted doing this job. What causes the failure, and what can I do as an owner to reduce the possibility of it occurring?

I might just start wearing a coat and hat in cold weather while using my car. Must have been a faulty design, or a weak plastic casting of the blend door.
Must really suck when it fails. Guys say its hot all the time, even with the AC on. What a freakin nightmare! $1500+ repair at the stealer.

To be honest, I don't have a problem in a repair like this because I like taking things a part. However, I've noticed with this car, in particular, that when you take stuff a part, things like to break.

It's almost as if they designed these parts to be assembled (or put together) one time only.

I wonder if I disconnected the electrical connector on the blend door actuator, if that would help to mitigate the problem? I hardly use the heat function of the HVAC knob as it is. I generally keep it on the coldest setting most of the time.

[polizzio]

Originally Posted by 152LTRockin

Just so you all know the REAL issue with the door breaking is because the actuator fails and does not stop but continues to force against the blend door until it breaks the door. The most likely preventive thing to do is replace the actuator before it fails internally and won't stop. I'm sure there is some type of feedback circuit built into the actuator to confirm its position.

As soon as I get time I'm going to pull a actuator apart and do some testing to see why they fail so much. If anyone has the factory manual with electrical schematics and other HVAC info would be a great help as I don't have the factory manuals.

I will find a solution and post it, if anyone has a broken blend door I'd like to have the old actuator to diagnose the problem and come up with a fix for everyone that's permanent. GM is never going to step up and fix the actuators, I believe they were designed to fail as crazy as it sounds. Gotta make work for their dealers.

It maybe as simple as limiting the amount of torque the actuator can apply if the feedback circuit fails.

I am familiar with electric and pneumatic actuators from a previous job. Many use physical limit switches to control the actuator. Or a torque/voltage sensing circuit, to stop actuator current when the hard stop is contacted, or before breaking something/overload. Evidently the Camaro blend door actuator does not have a current or torque limiting feature which would prevent failures. Too costly or deemed unnecessary for such a simple task. Something is most likely causing additional friction or binding of the blend door hinge/ pivot point over time. Or a mechanical blockage by foreign object (doubtful).

Still could be from long term heat from the heater core, something melting or fusing. Or perhaps the blend door pivot pin was lubricated from the factory with some sort of grease and over time and heat, or dust and dirt, the lubrication fails. The actuator does not suddenly just develop more power over time. Could be an alignment issue with the door/actuator/mechanism or linkage too, if there is such components.

One of the guys who actually repaired this, did the complete disassembly and eyeballed the configuration and details of the failure would have the best diagnosis.

[LevonH]

Originally Posted by DADs'_SS

Hi guys,

Ive done the repair myself for less than 100$!!

Here is a how to I have parts 1-5 on youtube. Feel free to ask me any questions.

https://youtu.be/KBV4cNpX8Rw

What a great bit of documentation. Thanks much. Hope I never have to do this but now know what's involved.
Vic, here is the link to all 5 videos you posted. Makes them easier to get to.

https://www.youtube.com/channel/UCb1...jI1laBJ85KZTHw

[LimaCharlie]

Originally Posted by gringo

Is there a way to keep this from breaking prematurely?

You know like not turning the temperture knob dial too many times to save wear and tear on the bend door mount from breaking?

I rarely use the heat function. So, I keep it mostly on the coldest setting (blue dot) part of the dash panel.

I've thought about this too. It's possible there is something wrong with the design of the door, actuator, etc. but I think 'user error' should be considered too.
I've seen people start their cars and QUICKLY turn their HVAC temperature dial to the full HOT position. It's possible the HVAC system can't keep track of where exactly the HVAC temperature dial position is and this can potentially make the actuator go beyond its intended range. Bottom line, it is a good idea to slowly turn up the heat instead of cranking it up quickly.

[152LTRockin]

There is a feedback circuit in the actuator. I never had one apart so I don't know the exact workings of it until I get my hands on one. I seen a video online that shows there is a set of wipers attached to the output gear. Those wipers get dirty and loose contact then the actuator moves too far in one direction. I'm going to try and pull the actuator from my car to inspect it and see how it works. BUT what I don't know is how the cars computer and heater controls calibrate these actuators. I talked to the local dealer they told me to remove the negative battery connection for 10mins that this will cause ALL the MODULES in the car to reset. Well that's too general explanation for me. I need to get my hands on a factory manual someplace. If anyone knows where I can get a copy or dvd etc of the manual please let me know.

I was thinking of simply adding physical stops to the actuator that limits its travel. I believe some actuators have this feature but they are not in the proper places to stop the actuator from breaking the blend door. The actuator can develop ALOT of twisting force.

[152LTRockin]

I put a restrictor in the heater core inlet hose to limit the amount of coolant flowing through it. The AC is quite a bit colder now even though my blend door is not broken.