Trailer Wiring Harness With Tinned Wire

Updated 08/31/2026 | Published 10/12/2019

Question:

I am also looking for a trailer wiring harness with tinned wires. Tinned wiring is used in the marine industry for corrosion ABYC standards all wiring in boats have to be tinned copper you cannot use standard copper wires in a boat so I dont understand why I cannot get tinned wiring for my boat trailer that gets dunked into the salt water no one seems to make a tinned wire wiring harness that would last 100 times longer.

asked by: Robert D

Expert Reply:

While tinned wiring is the norm when it comes to interior wiring on boats, boat trailers see a minimal amount of water compared to the actual boats. They do use a tin coating on the pins that are the parts of a wiring harness like the Wesbar 5-Pole Flat Connector # A40W5B since those are most exposed to moisture, but since the actual wiring is rarely exposed to water I'm guessing that's why they don't go the extra mile when it comes to using that wiring within the harnesses.

As far as I know, the only way to get a wiring harness that uses tinned wiring would be to purchase tinned wiring and hard wire that into a plug that you cut off of an existing harness.

expert reply by: Erik B

Bill B.

8/31/2026

This reply is not completely accurate. As far as water exposure and actual submersion, the wiring at the rear of a boat trailer is submerged every time the boat is launched. Interior boat wiring is normally tucked up under the gunwales or under the floor. This wiring may occasionally be exposed to spray or splash only during vessel use. Tinned trailer wire is offered by several name brand marine manufacturers. If you want the best choice in trailer wiring, search for and use tinned wire. It is much more expensive but if installed correctly and the connections are properly sealed, it is a one and done installation. Examples: Ancor 16-4 Flat Trailer Wire - ANC-154510 Seachoice Trailer Y Harness-Tinned-4 Pol - 13961