I built Boeing 747's and KC-46A's for my career. There isn't any ground at 40,000 feet, so grounds are critically important. I always check my wiring for a good ground. Aircraft also have the problem of developing static electricity at altitude and speed. We use static inverters, and dissipate the charge with leads on the trailing edge of the control surfaces. I worked on submarines, too. Try to find a ground at 400 feet below the surface. A good ground on your car will help in so many ways. I always use the ground strap between the block and frame, and always clean the ground surfaces when using a ground lug.
