Kinda had the same problem. Dealer replaced the T-stats and on/off switch. The switch had melted along with the wires behind it. What was the problem with your wires in the junction box. They actually removed my water heater to check everything. Just wondering if its something I should look at myself. They tested by cycling to heater, but who knows.
2013 Rockwood Ultra Lite 2703ws
2014 Toyota Tundra 5.7