I seem to have a issue with my window motor I've got 10v to the motor when the switch is depressed so I'm presuming the motor itself is faulty (It doesn't move at all and there is no sound ) does anyone know the replacement process?

 

Now would be a good time to add a automated signature to your account so that we don't ask you "what year, engine, etc" is your XJS?

 

Since you probably have the door panel off, best way to check if the motor is working or not is to unhook the two leads from the motor (black and red) and hook them up to a 12V source and see if they go up and down. If so, the motor is good. BTW, reverse the leads for up and down. If the motor makes noise but no movement, perhaps the glass is stuck in the window rails that may need adjusting. If no noise from the motor, probably bad.
good luck
Ken in WV