I've looked at a wiring schematic of one before and got a headache. Don't know what the point of it all was? My Dad had a 4010 Diesel when I was a teenager. He had our family mechanic who is a pretty sharp guy come over to do something to it and he was pretty dumfounded by it. He was a mechanic in the Air Force with 20 years experience after that by the time I'm thinking he was over so it certainly wasn't his first rodeo with 24 volt systems either.