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This is on my 2004 suburban with dual climate control.My driver side blend door would make a thumping sound while driving down the road. It finally would get stuck in heat instead of cooling. I found if I pulled over and shut the vehicle of and restarted out would reset the door.I eventually removed the blend door and took it apart. These are simple dc motor servos with a variable linear resistor to detect door position. Evidently when the vehicle starts up it runs the motors to both ends of travel for the doors. The problem is when the resistor contacts get noisy it can't detect the end of travel and sometimes jams the door. I opened mine up and removed the protective grease from the resistor tracks. I saved the grease to reuse it. I then sprayed contact cleaner onto the traces and manu…

This is on my 2004 suburban with dual climate control.My driver side blend door would make a thumping sound while driving down the road. It finally would get stuck in heat instead of cooling. I found if I pulled over and shut the vehicle of and restarted out would reset the door.I eventually removed the blend door and took it apart. These are simple dc motor servos with a variable linear resistor to detect door position. Evidently when the vehicle starts up it runs the motors to both ends of travel for the doors. The problem is when the resistor contacts get noisy it can't detect the end of travel and sometimes jams the door. I opened mine up and removed the protective grease from the resistor tracks. I saved the grease to reuse it. I then sprayed contact cleaner onto the traces and manually moved the brass fingers back and forth across the tracks. I replied the grease and put it back together. Works like a charm. This linear position sensor is much like a volume control on an old stereo that gets scratchy. Just cleaning it and replacing the protective grease fixes it. Now I am having similar problems with another door. This door directs the air flow from floor to upper vents and defrost I suppose. Works ok for about an hour or so then gradually the air flow stops coming out of the upper vents. Pull over shut it down and restart and the air blows full force again.

To strip the coating of of the wire use an aspirin tablet and your soldering iron. The acid from the aspirin will remove the coating. Just don't breath the fumes. This works on tarnished copper pcb traces and tarnished copper wire as well.

ust love our 3D printer for things like this. We've made replacement keypad housings for VFDs here in the shop. Also some plug in card handles for old VME bus cards. Do you have a thingiverse account?