Good info, but your suggestion reveals that more background is needed. I bought the truck second-hand about two years ago. Stock radio had the wires cut, so I bought a modern radio and followed a wiring diagram to match the new color schemes with the old Ford colors. The radio worked great except that the clock and presets would clear every time I turned off the truck, so I ran the yellow wire from the radio over to the fuse panel and spliced into a random hot wire (a buddy helped me here). Everything has worked great since then.
The dome light has never worked since I've owned the truck. Therefore, I'm wondering about the statement that they are both on the same fuse. However, I know all fuses are good at the current time because I pulled them all to visually check them.
The dome has two screws holding it on. Both go through some type of black plastic "connector" in the roof that have wires running directly into them.
Like I said in my last post, electrics are not my strong suit. What setting would I use to check the juice to the dome? Do I touch just one side or both terminals at the same time?