Okay guys on my 84 300SD, there is supposed to be power to the Clocking pump in the trunk all the time. But when I checked it today as part of my electrical trouble shooting for why the central locking wont work, I realized that it is not getting power. The pump works great when I hook it up to my 12V power source and all of the locks pull down and push up. Someone had mentioned that there is a connector that corrodes under the carpet in the rear passenger side but I cant find it- just the wires and the single vac line from the pump itself.

On the three wire connector that attaches to the pump, brown is ground, yellow is +12v with the driver's door unlocked and blue is +12v with the driver's door locked.

If you're not getting the +12 on the blue or yellow and the fuse is good, check the switch in the driver's door.