Hi,

Like I said, I couldn’t help you removing the mirror but it’s nice to know about the interior partition and rubber barrier.
I would think that those motors are fairly robust to where if they are getting power you should hear something? Is it only one that is dead?
Sorry!
I didn’t think to ask about what kind of problem brings you to want to look in there to begin with.
I can give suggestions or thoughts, like anyone else that has no experience! (:-)

On my 1993 it has two joy stick type switches down at the front of the parking brake lever console that are always getting something to land on them.
They are funky switches to boot!
I have had to clean them within a year car of getting the car three years ago. I got them to at least work without sticking but seems I can never remember which way to push them to get the right directions. Personally, I would never bought them as an option.

I have read that there are more problems with the wiring harness, that comes through the door hinge conduit, for other various things from time to time. The electric mirrors just add to this.
You.might want to disconnect the harness, from under the left side of the dash and check everything going that way into the door.
Wiggle or pinch the rubber conduit while using the switches! that hopefully, are in a nicer place than on my 1993!

Post back which way you continue your endeavors.

Phil