I will try to be as thorough as possible when explaining this issue, bear with me. I think it may be unique to my car because it's so damn confusing but I will throw this out there in the off chance someone stumbles along this thread who has seen it before.
The drivers side dome light (Honda calls it a spotlight, others call it a map-light, I call it a sling blade) stopped working. It stopped working both when pressed or when the door was open. The passenger side continued to fully function both when the door was opened (door activated) and when pressed at any time there was power to it. The bulb looked fine but I replaced it anyway to be sure since that seemed the most obvious. I felt like it wasn't "clicking" when I pushed it and I assumed it just wasn't making contact so I ordered a new base which includes the switch. In my case, the part number for this new "base" is 34404-SDA-A21. (Now, in retrospect, the light didn't work when the door was opened either, so obviously it wasn't just the switch.) In the picture below, the part I ordered is #11:
I got the part and got it swapped out fairly quickly (actually amazed how easy it was, I'm not usually good at stuff like this, get frustrated easily). It was really simple to do:
1. Remove the lenses (I used a butter knife)
2. Remove one phillips screw on each side (2 total)
3. Pull out the "base" a few inches to expose small electrical clips holding it there
4. Disconnect two clips (super easy, no prying required)
5. Remove middle section (contains "door - off" toggle) from the old "base"
6. Insert middle part into new "base" and re-attach
Both lights come on now when switched to "door" and the door is opened. That seems to be functioning fully. But now neither light will work when the door is closed. When the door is open, full functionality - I can press them on and off etc - but when the door is closed, absolutely nothing.
Obviously these lenses are meant to be buttons for the lights to come on while driving. There is a reason they call them map lights, and they are not meant to be limited to just when the door is open. I had full functionality of all of these lights a month ago. I have a hard time believing it is an issue with the new part itself. I talked the dealership into the part being defective so they ordered me a new one. SAME ISSUE.
This is what is really throwing me for a loop: I put the old "base" back in, and I got the original symptoms - Driver side not working at all, full functionality on passenger side.
If it's not a part issue, what is it? How can all the functions be working between the two parts but not all at once with either part? If it was a fuse it wouldn't work at all. If it was the switch then it wouldn't work at all. Scratching my head here.