Class A 330 diesel won't shut off

Roadpilot wrote:
We bought a new trailer for our MH. Had a Mobile Mechanic in Naples, FL. put in a connector to run it's lights and brakes. Arrived at our first destination and MH wouldn't turn off. tried everything including the mechanics switch in the engine compartment.

Then it occurred to me the only change lately was the trailer. Disconnected the plug and the engine stopped. The Mobile Mechanic had wired it such that the trailer battery for the brakes was driving the electronics in the bus. That cost me over $15K in blown stuff.

Who in Naples, so that I might not call him for anything ever?

I am working with the OP off-line with a possible solution having had the same situation. His DP is in the shop so it will be Monday before we know more.

Roadpilot wrote:
We bought a new trailer for our MH. Had a Mobile Mechanic in Naples, FL. put in a connector to run it's lights and brakes. Arrived at our first destination and MH wouldn't turn off. tried everything including the mechanics switch in the engine compartment.

Then it occurred to me the only change lately was the trailer. Disconnected the plug and the engine stopped. The Mobile Mechanic had wired it such that the trailer battery for the brakes was driving the electronics in the bus. That cost me over $15K in blown stuff.

wow that's amazing. what stuff burned out? and what was the actual cause in the end .it all sounds very interesting if you would explain
thanks

call cummins support.
All Class A Diesels engine are computer controlled PERIOD.
That being said, when you turn the key to off the computer then turns off a valve which is spring loaded. Thereby chocking the fuel off

We bought a new trailer for our MH. Had a Mobile Mechanic in Naples, FL. put in a connector to run it's lights and brakes. Arrived at our first destination and MH wouldn't turn off. tried everything including the mechanics switch in the engine compartment.

Then it occurred to me the only change lately was the trailer. Disconnected the plug and the engine stopped. The Mobile Mechanic had wired it such that the trailer battery for the brakes was driving the electronics in the bus. That cost me over $15K in blown stuff.

Modern diesel engines are controlled by some type of electronics and do need electricity to run.

Check your grounds first. When you turn on the lights, the ground is completed and engine shuts down. Also check ground on fuel shut off solenoid.

papasmurf005 wrote:
2004 Monaco with 330 Cummins that won't shut off. While the key is off engine runs, turn on lights or cruise engine shuts off. Alternator just replaced. Could this be ground problem or miss wired alternator. Also read about fuel pump solenoid cause problem?

Diesels don't need electricity to run. They won't stop running until the fuel is cut off. Something is keeping the fuel valve / solenoid from closing. As you say. It could be a short, which you really need to find. It could just as easily short the other way, and shut off the engine on the highway.

Moved from Forum Technical Support

Dennis, welcome and you may be in luck as I just had the same problem with my 04 Dynasty. 330 hp makes it a Diplomat? Are you familiar with the remote start switches in the back run box?