headlights are not working . ground issue ? 1973 dart slant 6

^^Yup. You know where both ends are. It is black no 18 wire, one end is the eyelet where it's bolted to (I thought the radiator crossmember?) and the other end is at the headlight connectors. As I said earlier, you can unwrap the harness a few inches, and cut off enough wire back from the lamp connectors, to make pigtail(s) and then bolt them to the fenders near the HL buckets.