Re: Unhook lights????
All my boat trailers have incandescent lights and I have never had a problem backing into the water with them plugged in. The housings are in good shape and don't leak. The only problem I have ever had was from corrosion on the contacts which is my own fault for not coating them with dielectric grease. As a matter of fact, one trailer has housings that are open on the bottom and I never have problems with those either. The bottom is open for reaching in to change the bulb. Its like pushing an upside down glass under water. I will admit that I only boat in fresh water, so salt water is another story.
Try pushing that glass underwater and shaking it around and tilting it at the angle of the boat ramp, it will lose nearly all of it's air.
Salt water gets to everything, it don't even have to be in the water to see corrosion, the humidity in the air near the shore that the trailer is exposed to while you are out on the water does a number on it too. Even my truck is well rusted after only a few years. If you open the hood, every seem and edge of every panel is rusted, all of the aluminum is white with corrosion and any bare steel is scaly brown with rust. I've lived around saltwater nearly all my life, you just get use to the fact that there's little you can do to prevent corrosion other than to wash vehicles often and keep after it as much as you can.
When it comes to lights, it's lots of grease and all connections need to be soldered and sealed with either glue type heat shrink tubing or brush on electrical tape. Bulb sockets rust out in a matter of months if not well coated with grease, (as do lug nuts and any other unprotected metal on the trailer), and the trailer wiring harness will turn green from the inside out and fail regardless what you do to protect it.
Certain things on a trailer become expendable in a saltwater environment, if not the whole trailer itself. Lights and fenders are sacrificial items, they just don't last long in saltwater.
LED lights have been a great improvement, and so far so good, but they still need to be connected to the truck. Just this year alone, two of my four wire plugs corroded off the trailer harness, I replaced two trailer wiring harnesses and two pair of fenders, and one cross member. The next most common item to fail is the rear rocker arms on a roller trailer.
I also had two rims perforated with rust after only 4 years, all were galvanized and brand new in 2004.
Saltwater eats everything, the chrome plating on the boat gets pitted, outdrives suffer damage and things like aluminum rails and plain steel hardware are just a bad idea. If it's not brass or stainless, it won't last.
