I have no clue when it happened because I removed the bulbs for the dome lights a long time back. When I rotate the dimmer switch all the way to the "interior lights" switch (full clockwise the little 'click' after full dimmer bright)

I did replace the dimmer switch a while back. It used to overheat and kill the headlights (would not blow fuse) The big connector for the dimmer switch was fine when I replaced the switch.

I put together a new headlight harness a while back, but got too busy with other things to get new headlight housings and do the install. I did clean the headlight harness connector on the DS inner fender today just to do it.

The 'dimmer' input on my aftermarket stereo harness is folded and heat-shrunk (verified today). The plug in the back on the hatch is unplugged and the ends heat-shrunk (verified today). I did find a black wire with a female spade connector that I covered with heat shrink. Something tells me it is connected to the dimmer switch. If it is, there has to be a reason I covered it with heat shrink and left it be.