[_Ogre]

as mentioned the dome light has a hot wire and grounds thru the headlight switch
connected to tab marked 'white-ground for dome light' connected to the small copper contact
the cam on the white plastic piece rotates down to push the copper contact down to touch the switch bracket

fyi... you only have a 4 fuse panel if your truck came with electric wipers, all trucks had a fusible link at the battery
a more basic truck only had 1 fuse on the headlight switch for the 'gray-instrument lights' tabs, this is the only fuse on the truck
the 2 bi-metal strips with points like contacts were the only other overload protection for the whole wiring harness
if you've ever had the headlights flash on/off it was the bi-metal strip heating/cooling
trucks with only heater or radio had inline fuses

if you want to add door pins i posted a tutorial in my build thread on how i made my brackets
i used some 10ga metal strips, bent in a vice with 60s door pins