Potential fire hazard

[Denny and Angie Miller]

While lowering my pin box I inadvertently pinched the break away switch wires with the bolts holding the pin box. I didn’t know this happened until several minutes later when smoke began emitting from the pin box and the battery compartment. Initially I didn’t know where the problem was and frantically began cutting wires that were melting in the battery compartment. Due to no fuse, the self-resetting circuit breaker kept resetting to the point the wire from the battery compartment all the way to the pin box overheated and melted all the insulation off. Since that wire is grouped and routed with many other wires (turn, brakes, stop, +12V) the hot wire melted into several other wires ruining most of the harness requiring a complete replacement from the pin box all the way to the battery compartment. Not a fun job as pulling new wire was complicated by the melted mess. I finally had to cut a hole in the closet floor to finish the job, which took about 12 hours. Initially I had intended to not reconnect the break away switch, but am now leaning towards reconnecting it through a 30-amp fuse as my factory brake controller uses a 30-amp fuse. That should be sufficient to prevent a fire.
What have you done differently? Any other suggestions?

[dieselguy]

It would have been an unwise move on your part not to hook up the breakaway switch. It is there on every camper for a reason. This may sound a bit cold, but the best solution to avoid mistakes during any job is to be very attentive to what you're doing, take your time doing it, and look it over really well afterwards. You also may want to look at a quick disconnect battery cable end terminal on the negative post of your battery. They only take a couple of seconds to disconnect.

[ChuckS]

Glad you were able to rewire the unit yourself... Things happen to all of us..

I would not tow that RV without the emergency brake circuit intact... if something happens and its discovered during investigation that the circuit was not hooked up for emergency brakes your gonna be liable...

https://www.rvia.org/system/files/me...quirements.pdf

Also if you are gonna put any sort of fuse in that emergency breakaway power lead the only thing Id consider is an auto resetting rated to match the current capability of the gauge of wire used in the circuit..

[BB_TX]

That is a hard one. The breakaway is an important safety feature in the event a trailer somehow came loose and should not be disabled. Not likely a trailer will come loose, particularly on a 5er, but possible and does happen. Fusing that line is not a good idea as you would never know if the fuse was blown disabling the safety function unless you put in a monitoring system for it. And ultimately you were at fault even though you did not know what you had done at the time.
I seem to remember one other instance of someone posting about a similar issue with that wire. Don’t remember the details. But it seems to be a very rare event.