* All 4 doors, the trunk, and the fuel flap lock and unlock as they should from the right front door as well as from the trunk. However, from the driver's door, nothing else locks or unlocks (the driver's door locks/unlocks mechanically just fine).
* I've replaced the interlock switch attached to the driver's door key-lock, part # 002 820 10 10. Also I've replaced the driver's door lock actuator, part # 124 800 21 75. The interlock function hasn't changed. Locking and unlocking the whole car still works fine from the RF door and from the trunk. But neither function works from the driver's door.
* I've seen the MB test sequence for the alarm system. That would take a long time and probably isn't necessary. Can someone who's been through this system please give me a shorter test sequence. Thanks.

Has this car ever had an aftermarket keyless entry system installed?

Also, has this problem always existed or is it something that just started happening.

Not sure I'll be able to help you, but I'll try.....

One more question: Is the interlock switch you refer to the same as S62/1 on the MB wiring schematics? (If I remember correctly, S62/1 is the switch that is accessible via a rubber plug on the back edge of the door)

* J.M., this car has never had a keyless entry system installed,
* I believe that this problem has existed for a while (more than a year) but I'm not sure, and
* I haven't found the locator number (S62/1) but you're probably right. Yes, access to it is through the rubber plug, which is also a bracket for the wire ends, in the end of the door.

S62/1 has no input to the central locking system. The function of this switch is only to arm/disarm the alarm and to activate the window convenience feature.

The reason I ask about the aftermarket keyless entry is because they are frequently spliced into the wire that runs from the contacts in the in the drivers door lock mechanism and the vac pump. I've seen some real hack jobs here--wouldn't surprise me if a connection came loose.

If it were my car, I would remove the rear seat to gain access to the vac pump. Then I would check to see that I get either ground or +12 on the wire coming from the the LF door. (don't have the schematic in front of me, but I think its the blue wire that comes from the LF door) With the key in the lock position, you should get a ground, with the key in the unlock position, you should get +12. This will at least verify the continuity of the wiring, and the function of the switch.

I'm out of time right now--I'll provide some more info later.....

J. M. van Swaay

* J.M., thanks for the advice to begin at the vacuum pump (under the rear seat bench), rather than the alarm control module or elsewhere.
* At the vacuum pump there are 2 circular wire connectors. One connector has 3 single wires, a blue, a green and a yellow. The other has 6 wires, 3 doublets, also blue, green and yellow. From the one with 3 single wires, the blue and the yellow wires were eaten in two. The third wire, a green wire, was hanging by a strand.
* I haven't reconnected the wires yet but I suspect that the repair will reconnect the driver's door. And hopefully all else will be well. The rodents have no doubt long since found new quarters in the owner's heavily wooded lot.
* I'll post a final reply to close out this job. Thanks again for your attention.

Final (FIX) reply,
* Repairing the rodent-damaged wires at the vacuum pump solved the problem. All modes of the central locking system work again (i.e there was no collateral damage).

Happy to hear it's fixed.

J. M. van Swaay