The best suspect is a rear door switch that is out of adjustment. Open just one door at a time, then press the switch to see if the dome light goes off. If it does, describe the switch, then I will tell you how to fix it.
The dome light is fed from fuse 13, a ten-amp in the dash fuse box, but it also feeds the cargo lamp and the visor vanity lamps. The visor lamps are on their own circuit with their own switches. The cargo lamp, however, is grounded along with the dome light, so both should be on at the same time.
The wiring diagram shows the circuit being grounded to turn the lights on, but there is no way to tell which of the two computer modules does that. There is an "overhead console module" and the instrument cluster.
The door switches are inputs to the Instrument cluster, then it appears the cluster sends a signal to the overhead console module. I cannot find the location of the module, but I did find the pin-out drawing of the connector. Use that to verify when you think you have found that module. What I think I would do is unplug the module. If the dome light does not tun off, suspect the instrument cluster or a stuck door switch. If the lights do turn off, we will need to take some voltage readings on the back of the instrument cluster to determine if a front door switch is stuck. Those are built int the latch assemblies.
Before we get to the instrument cluster, you may be able to get a hint by opening and closing the front doors. Watch for even the slightest flickering when the doors are being moved or when the door is latched and unlatched. That would indicate whatever you're doing is affecting the problem, and is pointing to the suspect.
Wednesday, June 7th, 2017 AT 10:30 PM