Rick,
Ken's suggestion is a good one.  I had the same problems two years ago
with my '90 Westy.  You don't have to even remove the door panel though
, just the switch will come out by itself, be gentle, and you can see if
it indeed detach itself from the harness. Good luck.
Russ

KENWILFY@aol.com wrote:
>
> Rick, pull the door panel on the driver's side.  Last time I had this problem
> come into the shop, the plug that attaches to the power mirror control
> switch, had come un-plugged (time and vibration).  I plugged it back in and
> all was well.  I then put some aluminum tape around the two plugs to ensure
> that this didn't happen again.  Took 15 mins tops.  I hope this is your
> problem.
>
> Thanks,
> Ken Wilford
> http://www.vanagain.com
> John 3:16
>
> New Phone (856)-327-4936
> Shop: (856)-765-1583
> Fax:     (856)-327-2242