Welding on trailer

[cumminstinkerer]

Interesting fact, I personally saw this happen to a coworker. He was welding auxiliary hydraulic tubing brackets on a brand new
Case excavator that we were adding the aux kit too, he was on the dipper, had the ground on the dipper itself, cleaned to bare metal at ground and weld points, welded the brackets and finished the install. He was already to test things out, climbed in and went to fire the thing up, it would only crank, several hours of diagnostics later, all leading to bad machine controller, we replace the controller with a brand new $10k one, fire the machine up and finish setting pressures, last I knew that unit was still going. That was a very costly bit of laziness, Case recommended unhooking the two main connectors on the machine controller and battery grounds, he wanted to save ten minutes by not do that, never did before and sure don't now weld on anything that has a computer on it without unhooking the main controller harness and the negative battery cables, if you don't want to take that time it could be your own big A oopsy

 

[bc]

Its low voltage and amps but same theory when trying to figure out why a trailer light ground doesn't work. Who knows where the electricity is flowing when dealing with paint, rust, loose bolts, rusted bolts, rusted metal faces. Same kind of who knows problem with electric fence grounds and somehow energizing horse and cattle water tanks. Or why the NEC decides when and where you do or don't need grounding conductors because of stray voltage.

Can striking an arc have a similar effect as a lightning strike where electrons go everywhere or when a power company transformer goes bad? We've got electrons floating around in the air. What if you were welding on a cloudy, rainy day with various charged electrons floating around? Think about Van de Graaff generators and what Tesla did with his coil and electrical generation.

Just saying. Nothing here except it can't hurt to disconnect the vehicle with a computer in it. Probably not worried if an IH460 was hooked up to it.