2004 MCI J4500 wont move

[oltrunt]

Windtrader, speaking as you are from the drivers seat of a 1976 MCI non multiplex bus I expect that you haven't had an opportunity to actually try hands on solving of an electronic failure on a multiplex bus while stranded on the side of the road.  Correct me if I'm wrong.  That said, solving the riddles of a multiplex system with an old skool multi meter is nearly impossible.  Prospective new bus owners would best advised that the purchase of a dealer level diagnostic system-one that includes complete wiring diagrams for each individual electrical system should be considered a mandatory option when purchasing a used computer controlled multiplex wired bus.  If nothing else, having the diagnostic system on hand would help the guy working at Bubba's garage in BF Egypt keep from trying to solve problems by throwing parts at the bus.

Perhaps all the computer stuff helps the environment--when it works but perhaps the real reason for the more "modern" design is that it saves the mfg a few bucks on the cost of wire while increasing the necessity for owners to keep bringing their equipment back to the dealer for all service.  Jack

[windtrader]

Jack,
My old bus no ECM or any electronics, all analog systems. My comment comes from the consumer auto technologies embedded in a cars these days. Much of the diagnosis and proper solution is provided by the data captured and reported, textually and codes.
Of course the reality is electronics simplify some things and makes it more difficult to sort out other vehicle problems. I'm about to shoot myself trying to troubleshoot a BMW ABS system, sensors, replays, ECM, too much. Primarily not swapping parts until very good idea of source(s) of the issue.

If I owned a bus with DDEC/similar, one of the first purchases beyond the essential repairs/parts/fluids would be the fully capable diagnostic tool to know what is being reports.

Whether a bus has modern electronics or none can be a great and lively topic. My guess there is a fairly weighty bias toward non electronics but the electronic versions must provide some benefits other than saving mfg. money. lol

[luvrbus]

Don the electronic engines and transmissions live 3 times longer now than the old machinal engines. Nothing to see gasoline engines running 3 to 400,000 miles and diesel engine running 1 to 1.5 million miles