Hi Jungle_Jim
yes Id say your right about the two black wires being the lives and neutrals as the switch will swap them over depending up or down .
as to removing the mechanisam yes its spring loaded but it seams to be weighted as it never srung shut on me , but take care just in case
you can remove the motor with out the mechanisam being touched though is quite fiddly , if you have access to an 8mm ratchet spanner there are three bolts holding the motor to the window mechanisam undo these and unplug the wiring harness to the motor below the speaker hole
then motr should be free
you will need to then strip the motor down make note how it came apart
where the two wires enter the motor there should be two metal strips making there way to the bushes that drive the winding one goes straight there the other one passes through the load resistor ,
unfortunately i didnt take any photos so can not show you .
just rap two fine threads of copper wires around the base of resistor then refit motor and try before refiting door card
Note that without any load the motor will work on the bench but i would still bypass resistor .
it is a damd fidly job though
you can also remove mechnisam easily enough but getting it back in is tricky too !
good luck hope it works these are just my expeirences but it does seem to be a flaw in the design
ps if your not sure wether its the switch or not just swap passenger and driver switch over they have the same conections
