97 Legacy Outback wagon with aftermarket remote starter. The dome light in my Outback doesn't work with the drivers door but works fine with the other 3. I've swaped the door plunger with the pass side with the same results. One thing I noticed is with the drivers door open when you open any other door the drivers door indicator will light up on the dash but not with just the drivers door.
One of the wires in the flex boot going from the door to the chassis has probably broken. Gently pull the flex boot back and look at the wires there. One (or more) may be broken off. Can't tell you which wire it is for your model, but I'm almost certain it is in that flex boot area. After years of being bent back and forth the copper work hardens (becomes less malleable and more brittle) and then finally snaps. The insulation is usually pretty worn out at that time too, so it completely separates. I had this same issue with the rear trunk door on an 05 outback I bought about a year ago. I usually say crimping and heatshrink is the way to go for wires that are in high vibration and stress (being bent and back forth) environment, but there probably won't be enough room for that. Put some heatshrink over one wire, solder them together, and then heat the heat shrink over it. If there are multiple broken off, hopefully they are all different colors. There were a few repeated colors in my outback rear trunk door, which made it a bit harder to figure out which one did what! Let me know what you find! This is just my best guess as to what the issue is...
I've started looking into this as well, as I have a 97 Legacy doing the same thing. Interesting thing is, the indicator light on the dash uses the same circuit. Signal (just switched ground) comes into the gauge cluster from the door switch on 4 separate wires for 4 separate indicators, then through 4 diodes to one wire, which then runs to the dome light. The fact that the indicator in the dash says the switch and wiring to it is probably intact. And the fact that the dome light works with the other 3 doors tells me the wiring to the dome light is functional. The only thing between the indicator light, and the junction of the 4 wires into one, is that diode. It is possible that a wire (most likely between the door and body) is breaking, and can handle the load of the little indicator bulb, but not the dome light. But I think the dome light would at least glow a little bit if that were the case.
Okay, isn't the door switch on the body, not the door itself. And it's only one wire to the switch, with the ground being the screw that holds the switch on the body? Look for Corrosion at the ground contact?
Good call! That wire doesn't run out to the door. Corrosion is certainly possible, but seems like you'd get something after swapping the switch...
