Here you were presented with the opportunity to learn something new Soundguy and you come back with this type of statement. It is confusing! I can recall reading a book by J.D. MacDonald and can recall some of his comments on some of the folks dwelling in the central backwoods of Florida. Will your fellow countrymen living in North Dakota, Maine, Vermont and similar areas of the US come under the same insulting comments!
Just to broaden your perspective slightly there are no Moose in the area in which I live, the South Shore of Nova Scotia. One must travel much farther North to encounter them.
In these frozen waste lands winter temperatures have a tendency to hover around the zero mark and we do get regular falls of 20 or more Cm's of snow that may be combined with freezing rain. As a result the Highways Departments use a lot of calcium chloride on the roads. The ensuing slush has a tendency to get into any and every crevice and start corroding. The trailer wires where they hook up above the back bumper are particularly vulnerable. Also the trailer plug is vulnerable from the back side as the cover on the front seals that fairly well. We are also subjected to moist salt laden sea air. Heck, I live 15 Kil. from the Atlantic Ocean!
The best is a soldered connection with shrink wrap and then the whole piece protected by another piece of tubing that is sealed at both ends. It takes time and care to do it properly and in many cases this is not done. The wiring on my trailer is all sealed as well as the lines going to the brakes. The only problem on it has been rust cause loss of ground on several fender lights.