We have a 2002 Monaco Diplomat 40PBT with the Cummins ISC engine. Last night on the way home from a trip, it died while driving. It had been running fine with no issues and without warning, the dash chimed, the lights on the indicator panel all went out, engine died and lost power steering. I was able to coast it to a safe spot. Though the engine stalled, the generator continued to run fine. We checked all the fluid level, rechecked the sliders, checked the battery voltage and everything looked fine. Both the house and chassis batteries were fully charged, so it didn't appear to an alternator issue. We still had over 1/2 tank of fuel. The fuel filters and fuel/water filter had all been changed within the last 1000 miles. We tried to disconnect the batteries and let it sit for a while then try to start it up. Nothing. No chimes or lights on the dash when the key was turned on, it was simply dead. Fuses and everything looked good. We finally resorted to having the coach towed home - ironically, it had died turning into our community, so the tow was about 300 yards! I tried it one more time to see if she would power up and nothing as before. This morning I went out to the coach to get something and tried to start it up. She started right up and purrs like she usually does. Everything seems to be fine this AM. I haven't driven it yet though. Any thoughts or ideas on the cause? Not feeling comfortable with the idea of driving it without knowing what happened. While doing some research online this morning, I saw two references to issues similar to this where the owner stated a 'weak relay' was changed, but no indication of which relay it was. Thanks in advance for any help!