Thanks very much, everyone. I haven't had time to replay back to all the posts yet, but there are a lot of good ideas here. And yes, the factory wire is pitifully tiny. "Myredracer" mentioned 18 gauge, and that's probably about right. The factory splices were terrible - just crimp fittings with no weather protection - so one of the first things I did to my new trailer all those years ago was to solder and seal those connections.
And no, there's no way 12-2 cable will run through the holes on my axle. Good points about following the springs, countered by the likelihood of damage by blown tires... Hmmm.
I'll come back to this when I have a little more time, but for now a sincere THANK YOU to all who took the time to answer.
Safe travels,
Regan
