Originally Posted by MIcamper
We have a 2014 Wildwood dbud. This is our 2nd year camping with it. This year decided to keep it at a campground for the summer. We have camped about 6+ times, so far. Saturday night around midnight, I smelled something strange. It was coming from our bathroom sink. It got steadily worse. I opened up the cupboard and smoke billowed out. My husband pulled the electric and then took apart the cupboard. It was the junction box. It was extremely hot. The wires around it were black, when it cooled down, he took the box apart and it was all black inside . Thank god we weren't asleep. I just don't understand how that could have happened. Took it to the dealer and they said it didn't look like it was from a surge or low voltage. Any ideas??
If it was just a junction box with no active components in it, You can pretty much assume that it was due to a loose connection. Looseness in a connection will increase it's resistance and cause heating. It's not terribly uncommon. In my plant, I take an infrared camera out and shoot IR images of junctions, switches and components. Sometimes its the only way that you can see the trouble brewing.
The picture below shows a typical problem spot on one of my 3phase motor starters. The image on the right show the starter under normal light. Looks ok... but in the IR spectrum, you can see that the black incoming wire is over 80c (175F!). This was purely caused by a loose connection on the black wire.
Its not something you can easily detect until it starts smoking, unless you have an IR camera.