Dont know about mods...
I was dealing with this...
When I found this
Looks like that tire may have taken a hard hit and when the u-bolt contacted the frame, it cut clear through the ground wire. I have things rerouted so that cant happen again. It happened a while ago, I remember noticing the tire had a funny shape to it months and months ago, but didn't realize it was starting to seperate. Trailer is only 16 months old, with maybe 5k miles on it.
Could have been way worse, I suppose.
2014 Silverado 2500 6.6L TD and 4X4
2011 Carson Standard Duty Car Hauler
2012 Forest River Stealth SK2112