I replaced all the brake wiring in my old trailer. I chose to wire it in a "star" configuration rather than the typical "daisy chain" which is OEM on most travel trailers. Yes, the brake wires that enter and exit an axle tube are prone to chaffing, either at the entry/exit points or inside the axle tube as the wire is bounced while on the road.
Now, I have a pair of wires from each axle, all terminated on the tongue, inside a box. If one brake fails, I can easily diagnose an electrical fault and more power is delivered to the brakes, also. All the underside wiring is laid in flex conduit.


Yeah, I know I need to get under there and remove rust. :B