Another rear door - door ajar problem...

[JoeBleaux]

The facts:

2006 F250 Crewcab Lariat
The rear door switches test good (with meter) and the connections are fine and in good condition.
When opening either rear door, the dome (overhead) light does not come on
Neither door being open triggers the "Door ajar" on the system monitor screen
It is not (so far) intermittent - they don't work.
The front doors work properly - the interior lights come on and if either is open, the system monitor properly ID's that fact.
All door locks work properly (with remote, keypad or door switch).
No other issues/problems observed at this point.

The only thing that might be related is that the locks and module that controls the door keypad entry was replaced (the "hard" code needed to be changed due to unauthorized person having it, along with a set of keys). Unfortunately, we don't know if the issue developed before or after this work.

It almost seems like the signals from the switches in the rear doors simply aren't reaching whatever they are supposed to reach, but since I don't know where the signal goes, I can't test that.

Has anyone seen this issue or have any suggestions what to try?