When in doubt, add a ground wire.

I'll double-dog guarantee you that there is enough paint, rust and grease on your dump bed to interfere with grounding tail lights, marker lights or whatever.

Drivin' down a 2 lane country road in a stovebolt.....cowboy, it don't get no better than this!

1946 1-1/2 ton Chevy
"Ol Blue", or "THE BIG 'UN"