66 dart electrical problems

Orange is the dash light feed coming from the light switch dimmer. Look at the radio connector. It goes to one of them. The oranges all come off one side of the 'inst' fuse which is at one end of the fuse panel

That is a trick circuit

The headlight switch has TWO separate power feeds TO it. One is headlights only

The second comes FROM the tail fuse, and powers tail, park, and dash lamps. That power goes through the switch, through the dash dimmer, and THEN goes to the inst. fuse on tan. Through the fuse, then out on orange wiring to all dimmer controlled lamps