I just spoke to a MB tech who stated that on my '86 300E, the electrical connection on the tumblers only engage the alarm systems. He also said the driver and passenger door actuator for the vacuum system provides the electrical signal to the pump which in turn provides the pressure needed to activate all locks... locking or unlocking them.
If that's the case, I believe the $50 door actuator is what I need instead of a $200 tumbler.
Any disagreement out there??