The activity of the door lock switch is very simple. By watching the signal at the door lock pump it should be easy to verify.

In the unlock position the blue wire will be hot. In the lock position it will be ground. The same signals are on the green wire for the right door and the yellow wire for the trunk.

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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician