Well for anyone interested, the mirrors can be stripped apart, there pretty basic apart from a little circuit board with the motor, I had the motor out the mirror and in my hand and had it running back and forth, grease all the mech and bearings up fitted it back together and nada

My suspicions are a broken wire is causing the lack of movement now, I'll too pee'd off to strip it all again so I'll leave it for a while and solder some new wires in when it really bugs me

Dissected mirror


All nicely assembled waiting for the clip to be put back on for the spring.