I have an 03 Taco and the dome light doesn't come on when I open the doors. It flashes briefly when I lock the doors but that's it. I checked the door jamb switches and they seem fine..not stuck and they look clean. I checked the fuse and it's not burned out. What else could it be?

I'm also trying to install a map light fixture with the middle 'door' switch from a 4runner but my plug on my 03 only has 1 wire. The light fixture from the 4runner has 2 wires. Any idea how I can get a hot 2nd wire to run up to that area?