Odd if you seriously look at all these ideas, one common things stands out. That being most every trailer lighting problem is tracked to the "grounding". And it is interesting to see that the ground is the single most problem of most every trailer wiring problem. But it also speaks to that fact that every light has a separate wire for the light's function, being turn, brake, or merely running lights. So it would seem reasonable that separate ground wiring would equally solve the ground problems as well. Some newer LED type lights actually have two separate wires coming out of their lighting unit. And therefore soldering a separate wire for that light's ground and running them along with the power wire to one common point is a very good thing to do. And then if you want to strap that to ground, do it at the same connection point. Almost all new vehicles now use separate grounds instead of the old chassis grounds like they use to be wired. Maybe there is a reason for that? Not trying to start any arguments, but merely pointing out ideas. When each light is strapped to a trailer ground at the light, there becomes many more areas to keep clean, tight and non-corroded. The statistically probability goes way up with each new addition trailer ground point for failure and that IS a fact. How many folks attach the ground wire to the bolt and nut that attaches the light to the trailer frame and most of the time simply stripped and wrapped around the threads on the bolt, and if the lights work initially, everything is A Okay. But that won't be A Okay a year later. It is how some folks do things. I've rewires so many bad trailer lighting problems and seen it. JMHO!