I'm no electrical expert by any means but, I don't think that should have power anywhere on the case. The case should be grounded very well when bolted down. A separate ground wire to the chassis is a good idea. Your ECU is more than likely shorted out. I'd try a known working one, albeit a crappy one. You don't want to try it with a quality one (There are ways to tell a good quality one from a junky foreign made one on this site) because it might ruin that too, if it's a problem with the wiring harness. I think HalifaxHops on here can help you. It looks like you're working on a Dodge van.