In article a8ccf3c0-996e-4601-a0b3-22e55ecef387
@b13g2000prf.googlegroups.com, says...

Tried to install the new lights on my trailer only to find all the
wiring eaten up by corrosion and all the connectors on the trailer
corroded. None of it was tinned wire. This is OEM wiring in an EZ
Loader trailer so beware.
So, Does anybody sell wiring harnesses with marine tinned wire or
should I simply make my own?

If you had a special trailer like Harry, that wouldn't happen.