After wasting time digging in behind the door panel and the switch unit, which is an intricate printed circuit, I had to use the grey matter once again.

I did not want to dig into the wiring too much, let alone cut wires etc.
During my fiddling about I noticed that the mirror adjustment switch works with the key in ACC2 position – so I knew where to get power from.

The fuse box seemed like the obvious place to start. I located the window fuse (position #8), and the mirror operation fuse in position #23. All I needed to block the power from the live part of fuse #8, and bring in power from fuse #23. I used a ‘blown’ fuse in #8 position and took power from the downstream side of fuse #23 (so the windows are protected by the 7.5 amp mirror fuse), and into the downstream side of the #23 fuse.
The piggy-back is achieved by some ‘elegant’ soldering onto the back of the fuses, and insulating again using a glue-gun.
The piggy-back looks a bit agricultural, but it works 100%. The beauty is that the modification is fully reversible in 10 seconds by changing back to 2 new fuses in #8 and #23.
