I believe that they are motor/gear driven - more or less like pop-up style headlights. When you turn the headlights on the motor turns the gears and they pop up and then when you turn them off the polarity isn't reversed, the gears are driven forward until they come to a reset position. I'm pretty sure these cut-outs are much the same way. On other forums I read where the motors sometimes went bad, but that could be a heat related issue as they were being used on turbo cars.

Either way I wish you luck and keep us informed :-)