Just had an electrical fire in my 2006 Grandby. Thankfully had just parked, climbed in the camper and popped the top when smoke started billowing out of the cabinets from just about every opening. Main power switch was OFF. Took me over a minute to disconnect the negative battery cable. Thankfully, I was able to stop the fire with minimal effort; ie: no extinguisher needed.
It appears that the ground/negative wire running from the first grounding block/terminal (next to the water pump) to the back of the IOTA fuse/power center completely melted its insulation off along the entire run. This wire was loose at the connection to the back of the IOTA terminal. I assume that this loose connection caused a spike in resistance and the wire heated beyond its capacity.
I have now disassembled as much as I can to access the full wire run. This wire is poorly spliced in several places, some splices include a connection to 2 or 3 other ground wires along the run. In addition, this wire is severely undersized. It is a 14 AWG wire supplying the negative connection to everything running off of the fuse block.
My plan is to replace the entire run with a doubled 12 AWG marine-grade wire and re-wire all of the individual splices with their own ground wire running to a new terminal I will install behind the IOTA fuse center. I'm hoping that there aren't any unseen issues with other wires. So far it seems like all of the other wires insulation remained intact during all of this.
This camper smells horrible, and the wire melted through the non-pressure water-tank fill hose, so I'll have to replace that, as well.
It could have been worse...