ISC 350 Started by itself. Any ideas?

[billg72340]

2000 Winn on Spartan Mountain Master GT Chassis with Cummins ISC-350. After washing engine compartment I drove 5 miles to storage and parked. I get a call two hours later saying the coach is still running. I went back and found it had died but had started unattended and had indeed been running without a key in the ignition. I disconnected all the batteries and let set for 2 days. I figured something got wet and triggered the starter and may work after drying out. I found the starter had stayed engaged and was damaged which I replaced however the problem is still present. The Ignition wire to the starter solenoid has power all the time. I suspect a chassis mounted solenoid or relay is stuck but have been unable to locate without a Spartan wiring diagram. Any ideas as to where to start? Anyone have a similar Spartan wiring diagram willing to share a copy?
Thanks
Bill G

[DonnaB]

In 2008 we had an incident where the starter started engaging after we had stopped for the day. We had driven thru rain and believe the fuse box in front of the rear axle had gotten wet, causing the starter issue. Had to keep the batteries disconnected until we were ready to move. Used a hammer to tap the starter as it kept trying to engage and that finally stopped it so that we could actually drive to the repair facility as opposed to a tow. We were under warranty at the time so Spartan authorized replace/rebuild the starter and they later replaced and repositioned the fuse box to mitigate the leaking issue which they felt caused the problem to begin with.

If you call Spartan customer service and give them your VIN, they will email you complete drawings for your chassis.

[Ronnie Bledsoe 2006 Dutchstar 43']

I had the same problem and the cause was the fuse box which in my case is about 4" square and located fwd of the batteries in a small storage bay. I had to replace the starter and fuse box. Mine was covered by warranty. Spartan had notified Newmar that the fuse box needed to be relocated from its floor mount to the sidewall of the storage compartment. It had not been done and water accumulated on the floor of the compartment causing a short...starter engaged and attempted to start the engine until I disconnected the battery. Too late to save the starter.

[billg72340]

Update

Problem solved. Spartan e-mailed the wiring diagrams and it was no problem tracking down the power source. It was a small relay on the inside of the frame rail about 3' from the starter that was stuck closed. New relay and new starter and everthing is back to normal. Thanks for the help.