I recently put a Valet 561R into a 1996 E320. This vehicle is equipped with the Benz factory alarm. I can get everything to work properly except the door locks. I actually have them working, just not properly. I found two wires (blue for disarm & brown for arm i believe) in the driver kick panel that show ground when the key is turned in the door (arm & disarm I presumed?). I hooked up the 561R's factory disarm/arm wires to these two wires and now the factory alarm arms & disarms and all doors/trunk lock & unlock EXCEPT when the vehicle is remote started. Upon remote start, all doors unlock and cannot be locked again by either factory remote fab or 561R remote. I searched high & low for these blue / YELLOW, blue/black wires that are posted for this vehicle to lock & unlock, but I couldn't find anything. Is it just me or is Mercedes a wiring mess? Factory wire ties not snipped, driver door sill a rats nest of loose wires. I have tried going to the interior lock/unlock switch on the dashboard, in which I found a WHITE/ green wire that locks and unlocks the doors while the car is running. When I press unlock, the WHITE/ green wire shows ground & 6ohms of resistance, but I cannot figure what it is doing when I press lock. Here is the diagram Mitchell On-Demand gives me for that switch:
It tap ground to this WHITE/ green wire and it just unlocks the doors. I cannot figure out how to lock...GRRRRRR!!!! If anyone has any clue what to do here, please let me know!! You feedback is greatly appreciated! One more thing, the customer complained that his factory alarm started going off while he was driving! wth?!?! I don't know how this could have happened nor have I been able to reproduce this phenomenon.....I HATE BENZ!!!
NOTE: When measuring for resistance, I hooked the multimeter up to the brown wire and the WHITE/ green and applied the switch to the lock position then the unlock to get my readings.. this is how to measure, correct? I only get a reading on unlock of 6ohms..and when ground is applied to this circuit (whether through 60hms of resistance or not) all I can get it to do is unlock. I NEED LOCK!!!
It's 200 ohms through the white green, I think there might be a keysense wire to disable, you also got things like acc 2 ign 3 coming off the ignition switch. On a standard alarm I go to the blue and black and extend the black time for total close. In UK dealer installed alarm went under the passenger floor panel.
Can't remember which way round!!

Try both ways, it won't hurt if you've got it wrong. N.B. I pop out the door contact and disconnect 1 terminal, remove key from ignition and throw door lock latch otherwise it won't test properly.