Terrible factory splices in brake wiring

gmw photos wrote:
On the subject of wiring, here's a suggestion I make to all new trailer owners. Spend the time on your back under the trailer to inspect all the runs of wiring. On my trailers ( all of them: travel trailer, two horse trailers and one flat deck equipment trailer ) I found places where wiring was run thru hole in the frame or around other edges where the wire could chafe and sooner or later rub thru the insulation causing a short to ground.

What I found in the axle tubes was small rubber grommets. Great, except they don't have a groove in them and just push in. I wasn't going to use them but I couldn't get them to stay in place at all. That means the #18 wire with it's thin insulation and no overall jacket is subject to chafing and could eventually short out or break.

I don't understand how the axle and trailer manufacturers can do this.