Dutchmen Trailer Electrical problems by year

a trip with my trailer, I parked it at home and started investigating an overload in my 12 volt system. I could not find any issues with the 120 v ac to 12 v dc converter. However, I found a burned wire nut on the floor of my trailer. Investigating further, I found that the 120 v ac wiring appears to have arced resistively (hot to green safety ground) underneath the dinette in the slide-out room. I use these specific terms because no circuit breaker was tripped and the wire nuts show obvious signs of burns. The trailer manufacturer used an soj (extension cord) type cable between two junction boxes, and this cable is not secured anywhere between or inside the two junction boxes. Only the wire nuts holding the three conductors of the soj cable to the romex fixed wiring hold this cable in place. The cable is used because it is linking the stationary trailer floor with the slide-out room. I think that the circuit arced because of the movement of the slide-out room pulling the soj cable. I have owned the trailer for just over a year and have deployed and retracted the slide-out room dozens of times--it's necessary to do so to use the trailer as a temporary living quarters. The trailer is at an rv dealer (poulsbo rv, ridgefield washington) right now, being repaired. I have voiced my opinion to the dealer that I think this is a poor design that could be unsafe, and have asked them to contact the manufacturer to have the repairs done at no charge.