I have a 2006 Roadtrek Adventurous RS with dead electrical system on the vehicle side. The problem is intermittent and results in no idiot lights, radio or start. The battery has been load tested and checked good. I checked and ruled out ground faults. The battery terminals have been thoroughly cleaned. The warning bell occasionally rings when the door is opened. When turning the key to the ignition position. I sometimes see tach and speedometer needles jump just a tiny bit but no panel idiot lights at all. Once it started 20 times and then failed again. I suspect may be a safety lockout switch or ignition switch.
This clip show the discrepancy I'm experiencing.
https://youtu.be/6QruyriakxE