I had the belly tank, what a pain. you can only fill up here if the truck is inside of the fenced in area. barbecue places can't fill it. not worth the headache. i'm way ahead of the game over my last simple truckmount cost wise when you figure in the two engines and propane. neither machine caused me any lost jobs because of down time. still don't like the cheap switches.
i'm no engineer but the marine industry, auto indutries, virtually all electronics use relays, must be a reason. If a switch goes bad you cAN JUST connect the wires.
gene