Removed, dismantled and cleaned the guts of the volume encoder with alcohol and toothbrush, and soldered back on the front panel printed circuit board. Somewhat delicate surgery but works as new now. (Did it months ago but found the pictures just now)

 

I did that years ago but it didn't last long. I just bent the tabs on top without unsoldering the component. I was looking for a new potentiometer but these are impossible to find. It looks like a part specifically made for Alpine.

 

I did that a while back to my 99 D2 it worked with no issues, but I used the steering wheel controls more anyways.

 

DeOxit won't accomplish the same thing less invasively?

 

Hi. 99% sure fluids would not flow inside, zero invasive in there, nor dissolve/rinse the hardened grease inside, nor purge it out, nor clean anything... There is no openings for cleaners to enter or sheet to exit. And with an unobtanium part, see dismantling as a mandatory surgery