AC problems

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#16
Reminds me of another GM vehicle with a jammed mode door, removed the top of the dash, and the cover, and found a piece of foam with self adhesive that fell of a piece of plastic mode door. Nothing wrong with the foam, not torn but caught between that door and the housing. How did they expect this to hold with 195* heat on it.

First attempt was to glue it on with contact cement, that didn't last very long, second attempt, after gluing again, I cut a piece of 20 mil aluminum sized to fit inside of the frame with the door closed and riveted it. Sandwiching that foam, this lasted.

May or may not be your problem, don't know until you look. 98 Ford Explorer had a like problem, but they used the wrong grade of plastic for that door, it warped. This was a mess, had to remove the evaporator box first that not only required removing it, but recovering the R-134a first.

To get at this varies by vehicle, need an alldata.com subscription to learn what you have to do.
 
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#17
Reminds me of another GM vehicle with a jammed mode door, removed the top of the dash, and the cover, and found a piece of foam with self adhesive that fell of a piece of plastic mode door. Nothing wrong with the foam, not torn but caught between that door and the housing. How did they expect this to hold with 195* heat on it.

First attempt was to glue it on with contact cement, that didn't last very long, second attempt, after gluing again, I cut a piece of 20 mil aluminum sized to fit inside of the frame with the door closed and riveted it. Sandwiching that foam, this lasted.

May or may not be your problem, don't know until you look. 98 Ford Explorer had a like problem, but they used the wrong grade of plastic for that door, it warped. This was a mess, had to remove the evaporator box first that not only required removing it, but recovering the R-134a first.

To get at this varies by vehicle, need an alldata.com subscription to learn what you have to do.
NickD, I think your right and that something is stuck jamming the said actuator mode and preventing it from doing it's job. Hopefully, I destroy the whole dashboard trying to get to the specific location and hopefully it does not become an additional unnecessary financial burden. Thanks for the great information though.
 
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#19
So, I just got my truck's AC and HVAC system diagnosed and finally got the problem fixed. After the diagnosis was done both the AC and HVAC systems were found to be in normal working condition. The only abnormalities found was that a Ballpoint pen had somehow gotten stuck inside the air duct system and was causing one of blend doors from properly shutting close in order to redirect the airflow up towards the windshield side air vents during the defrost/defog mode. This also caused one of the actuators (unit located by the accelerator pedal) to pop halfway through the process while switching over to defrost/defog mode. Anyhow, I just wanted to post this wonderful update and I want to thank everyone for the great response and assistance which I greatly appreciated.

Oh! before I forget, does anyone know what causes a high pitch intermittent humming noise coming from either inside or behind the dashboard area? It comes and goes while I'm driving around town at speeds between 15-45mph. It goes away as soon as I let go off the pedal or whenever I step on the brakes and then comes back again as soon I press on the gas pedal. I've tried disconnecting both the Stereo and AC control panel and it still happens regardless. Any suggestions or advise is greatly appreciated
 

nickb2

Wrench. Diagnostic Tech.
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#20
After the diagnosis was done both the AC and HVAC systems were found to be in normal working condition. The only abnormalities found was that a Ballpoint pen had somehow gotten stuck inside the air duct system and was causing one of blend doors from properly shutting close in order to redirect the airflow up towards the windshield side air vents during the defrost/defog mode. This also caused one of the actuators (unit located by the accelerator pedal) to pop halfway through the process while switching over to defrost/defog mode.
Somehow I knew this was going to finish this way.
 

nickb2

Wrench. Diagnostic Tech.
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#22
Ok, so this is NOT an AC problem, but more a HVAC problem.

By this I mean, you are experiencing problems with the delivery of cool air. So that means the AC system at its base is working. But your controls are not following what you want them to do. That is good news.

This is most likely a door actuator problem or a AC control panel problem.

An easy and funny way to check for actuator calibration is to remove the HVAC/ECAS fuse for 10 seconds key off, reinstall the fuse and start the engine, then wait 40 seconds for the HVAC system to re-calibrate itself.

I am not the kind of guy who likes to say I told you so, that gets boring after awhile. So, (I told you so back in july)

Since I am feeling feisty and don't know why nuclear shit needs to happen, lets laugh for RIP