How to fix HVAC control Panels with faulty switches

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LordWayback

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Foreword: precision repair if not done correctly it’ll be broken but if the panel is already broken it doesn’t hurt when you were going to replace it.

I figured out how to fix one of the biggest problems at least temporarily if not permanently! Required tools and Materials
1. Precision needle nose pliers
2. 8mm?
3. Very very tiny flat head
4. Q tips name brand or not doesn’t matter
5. High percentage rubbing alcohol
Step 1: Remove from vehicle
Step 2: remove all screws from the back and the blower motor potentiometer that goes all the way through the back
Step 3:remove all of the potentiometer caps (the plastic switch things that go on the outside)
Step 4: lift the black cover gently and set like this image.jpg
Step 5: pry the metal tabs up on the broken potentiometer and PULL ON THE METAL NOT THE PLASTIC
image.jpg
Clean the black pad and the golden points on the bottom of the switch with rubbing alcohol and q tips and then repeat the steps in reverse until it’s connected and test it if that doesn’t work you most likely need to junk the HVAC panel because it’s a issue with a diode that needs special attention that’s not worth your time without the skill to do so.
 
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LordWayback

LordWayback

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The reason it gets dirty and stops working is because there’s nothing sealing the metal and plastic together besides tension from the metal flaps and will cause no response or only in a certain spot or if you move it aggressively
 
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LordWayback

LordWayback

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The black stuff is what you’re hoping to clean it prevents a good contact aka electronic signal.
image.jpg
 
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LordWayback

LordWayback

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The first pic with the backside kinda looks like a manual unit, not auto.
I believe it is a manual unit based on what I have heard it should cover 2000-2002 model(s) this one came out of a 2001 Gmc Yukon xL W/rear air.
 

Fless

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Best to use one of the DeOxit products (e.g., D5) so that the contacts are cleaned AND lubricated for contact longevity. A cleaner that leaves no residue will allow the contacts to oxidize quickly.
 
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LordWayback

LordWayback

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The first pic with the backside kinda looks like a manual unit, not auto.
If someone sent me an automatic unit they’re gonna junk I’d be willing to mess with it the automatic units have a tiny circuit fuse a .25 mah that completes the circuit (put a fuse on the power wire of the automatic unit and jumper the fuse) and will make the whole thing not work.
I did some schematic digging and that should be the first thing to stop it from working, however i believe the only difference on a broken knob is the potentiometers the automatic units use a 359* potentiometer (source needed) and a similar technique can be applied.
 

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