My Chevy Impala started a clicking sound under the dash. It stopped after a while, but would start up again if you changed A/C Air Conditioning settings.

If the clicking starts when you turn off the key, or change the A/C from inside to outside, or outside to inside, it is the motor on the right-hand side of the glovebox.
If the clicking starts when you change the temperature or upper/lower settings, it is the motor on the left-hand side of the glove box.

It's an easy fix either way.

Tilt the glovebox door all the way down. Change the A/C controls until you hear the clicking sound coming from under the dash. While the clicking sound is being made, touch each motor to figure out which is broken.

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Left-hand Motor. Not clicking on my car.


I am going to remove the right-hand motor, it's clicking when I switch from outside to inside(recirculation) air. First lift the tab up on the wiring harness plug, and remove the plug.


Locate the two screws that hold the motor to the A/C unit.


Remove the two screws using a 7/32nd short socket on a 1/4" ratchet. Then slide the motor off the shaft.

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With the motor removed, pry the clips back around the case to split the case into two halves. You can also make note of the part#. It is the eight digit number on the white sticker. In my case, the part# is 52411997. This part# is common on VERY many GM cars. Pontiac's, Saturn's, Chevy's, Buick's, GMC's, and many different models.

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With the case open, you will see that one or two of the teeth are broken off the intermediate gear. You have three choices here:
1. You can go to a GM dealer and order a 52411997(Verify part# on your make and year. It's on the white sticker) for $170-$270.
2. Search Ebay for 52411997 and find new ones for $79, or used working ones for $15-$25.
3. Repair the gear yourself.

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Repairing the gear yourself

Use a Motor Tool to cut out the bad teeth. Be sure to cut below the gear surface so the epoxy holds. Next fill the void with plastic mend epoxy. Wait for it to cure, then use the Motor Tool to cut the teeth back in. If you choose this method, be sure to install the gear back in the case at a slightly different rotation, since the gear gets the teeth ripped off by the A/C door hitting the end of its stroke while the motor continues to run. You don't want it to hit the end of its stroke right where you have replaced the teeth, or it will break the epoxy out.

Install the repaired or replaced motor back in the car, connect the wiring harness, and you are ready to go!

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Final Thought - This is a really piss poor design. The intermediate gear only makes contact on 1 tooth, and the smaller gear on the motor strips the tooth off right at the end of the stroke.

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