In Reply to: 8N Rear Lights ? posted by Bob on August 23, 2018 at 15:07:09:
As others have said, no ground.
6 or 12 volts has no bearing on the problem as long as proper bulbs are used
Most likely places to look are corrosion in the light housing, mounting brackets to the fender, or dirt and rust where the fender attaches to the axle housing. Can either clean it or bypass it