The passenger side electric head rest on my W124 seems to have given up the ghost, and after some investigation I'm stumped and need of help as to the where the problem lies. I've taken the back of the seat off o.k, and the motor tested o.k. There is continuity across the terminals, and testing form each terminal to the body of the motor showed open circuits, so I assume there are no internal shorts. The mechanism seems to be o.k, with no apparent damage to the plastic rack and pinion arrangment. when the switch is operated there is no noise from the motor. I changed the electric seat switch on the door card with a replacement form mercman which hasn't solved the problem. All of the other seat adjustment functions work as they should. Hardly a big deal, having a headrest stuck in the up position, but I'd like to get to it fixed all the same. Does anybody have any ideas of other things to check/test before I throw in the towel and give it to a sparky to a deal with? Thanks, James.