[SOLVED] A/C Mode door actuator re-index success + extra inf

[KE7WOX]

So last year I developed the issue with the mode door, however, never got around to fix it since I had little free time. This year I finally purchased all the tools (or borrowed some) and fixed it today.

I used the information found here (GMTNation) but I would like to add more information here.

1. Tools
-I borrowed a 3/8" drive thumbwheel ratchet, I felt it was a lot easier to remove one of the screws with that one. There is barely enough room for a standard socket + 3/8"->1/4" adapter, so I think that a 1/4" drive would be much better.

-Miniature test clips for the multimeter make it a lot easier, since you can clip the pins and move the pot gear while simultaneously getting a reading on one of the pins, then you only need to remove them for the fine tuning.


2. Values

When out of calibration, the resistance between 2 pins was ~8.64kΩ, no reading between the other 2 (no continuity either, as expected). I did not take note of which pins it was, as I was also troubleshooting the leads on my DMM.

When calibrated, my resistance values were 4.77kΩ and 4.78 kΩ. Close enough.

A CCW rotation of the pot gear resulted in an increase in resistance between pins 9 and 7. The gear is extremely sensitive to changes in the angle.

3. Other recommendations

I put tape on the actuator casing and scribbled some alignment marks on the actuator lever. Even though you can move the potentiometer gear without entirely moving the actuator gear, I decided to be on the safe side.
http://www.felipe-garcia.net/wp/wp-cont ... 205134.jpg

I also put alignment marks on the pot gear and the motor, I think this is pretty important since the gear can move during re-meshing, this way you can realign it easier should it move too much. After remeshing all the gears and closing the actuator for installation, the resistance between 9 and 7 was at ~4.85kΩ, so there was a minor change. I also wrote down the approximate equal resistance value. This mostly to make my life easier, should I need to fix this actuator again at some point.

This is how I put the alignment, and this was also the position that resulted in approximately the same resistance.
http://www.felipe-garcia.net/wp/wp-cont ... 205101.jpg

4. Expenses
Craftsman multimeter 82345 - $16
Craftsman DMM test lead kit - $19
Rayovac headlamp - $20
1/4" drive ratchet ~ $10
-------------------------------
Total cost of the fix ~$65

Never got a quote from a dealership, but based on what I've read, I probably saved at least $700.

5. Attributions
"shadowjig"
Bill "the roadie" Carton

//I will embed the images after I resize them.