Reliable ground, yes or no?

I know, you think I'm getting paranoid about this grounding stuff, internal/external washers etc.
BUT, check the image below, if the parts were primed and painted before assembly, and they very likely were (at least primed, I have checked other assys), what kind of ground path is provided by the fasteners shown? It is the return path for the tail light assembly on the 8x8. Similar situations exist on the deuce and other MVs, take a closer look.

The solution here is to use int/ext tooth washers or add a properly installed ground strap.

Just trying to explain my obsession with star washers of the right kind...

PS. A note about the image, the box was mangled and was straightened by yours truly, it came from factory straight. "Box" on the left and frame on the right. Cap screws provide the (accidental?) ground path.

On the class 8 trucks of today, the tail light x member is either riveted, bolted or huck bolted to the frame rails with no washers between the x member and frame. It was most likely assembled then painted. The unpainted surfaces clamped together provide a ground, but, the lights have a ground plug on them and they are not grounded thru the mount they are on. They work if they are not even touching the truck. The lights on our MVs are the same. There is a separate ground wire to the light, but, if the main ground that is the return path for all of the grounds has high resistance or is failed, then nothing would work, or there would be funny things happening like when the left turn signal flashes, the right side dimly lights too. Ground are extremely important and will cause major headaches. Cummins was having so many ground issues with the vehicle manufacturers that they made a 10a ground circuit fuse into the engine harness. If a truck came in with power related complaints and faults and you checked the fuse and found it blown, you knew right away that a major OEM ground had failed.

As part of my painting and general restoration job, I'm renewing all grounds that I can find... New bolts, star washers, and metal lock nuts and I sand the frame and parts to shiny metal before assembly... Then touch up with paint afterward. My truck has an issue with both front turn signal lights coming on when the brake pedal is pushed, hopefully this will stop it.

I'm probably going to re-do it all over again now that I know where to get the correct military-type star washers... My local bolt shop sold me the regular ones.

Jon

Good going Jon! I think you'll gain a lot of confidence in the process, learning about an otherwise hidden and "taken for granted" electrical circuit.

I worked on my 105 trailer couple weeks ago. I turn signal bright, the other dim at the same time. Ground wire in power cable was not hooked up and it was trying to ground thru pintle. Fixed ground and lights work fine.