Seamaka 26FT Trailer Wiring Harness 4-Pin 5-Wire — Jacketed 16AWG Cable, Marine-Grade Durability

Seamaka's 26-foot 4-pin 5-wire trailer wiring harness is a heavy-duty, jacketed cable kit that connects both-side taillights for trailers, RVs, and boats.

When rewiring a trailer or adding a longer extension between tow vehicle and trailer, a reliable cable that resists abrasion, moisture, and corrosion matters. This Seamaka wiring harness provides color-coded connections, a durable PVC jacket, and a long 26-foot length to reach common hitch configurations on boats, horse trailers, utility trailers and ATVs without splicing multiple shorter cables.

How does this harness make trailer light wiring easier?

The harness comes with a standard 4-way flat plug and clearly color-coded 5-wire leads to match brake, turn, tail, and ground circuits. That reduces guesswork during installation and lets most DIYers finish a rewiring job quickly with basic tools.

• 4-way flat plug fits common trailer connectors
• Color-coded wires speed up matching and testing
• Includes a 2.5-foot ground lead for secure chassis grounding
• 26-foot main cable eliminates need for extra extensions

What makes the cable durable for outdoor and marine use?

This harness uses a thick PVC outer jacket over copper conductors to resist chafing, UV exposure and moisture. The construction and 16 AWG size balance flexibility with the current capacity needed for standard trailer lighting circuits.

• PVC insulation and sheath protect against abrasion and weathering
• Copper wire cores provide reliable conductivity
• Rated for -22°F to 221°F operating temperatures
• 300-volt rated insulation for secure low-voltage use

Which trailers and setups is this harness compatible with?

The Seamaka 4-pin 5-wire harness is intended for vehicles and trailers that use a 4-way flat plug for lights and require a separate ground lead. It works well for boat trailers, cargo/utility trailers, ATV haulers and many horse trailers.

• Compatible with standard 4-way flat trailer sockets
• Suitable for rewiring both-side taillights and turn signals
• Designed for multi-purpose trailers including marine use
• Not for 7-way round/flat brake-control power applications

How should I install and test the wiring harness?

Route the 26-foot jacketed cable along the trailer frame and secure with clamps or zip ties, attach the 2.5-foot ground to a clean metal surface, then plug into the tow vehicle. Use a circuit tester or have an assistant operate lights while you confirm each function at the trailer sockets and lamps.

• Clean mounting points before attaching ground wire
• Keep cable clear of sharp edges and moving parts
• Test tail, turn, brake, and ground functions after hookup
• Trim and seal any cut ends to prevent water intrusion

Who is this for? If you tow boats, ATVs, utility or horse trailers and need a straightforward, long-reach wiring solution, the Seamaka 26FT 4-pin 5-wire harness is built for DIY rewires and replacements. It’s aimed at owners who want a weather-resistant, color-coded cable set that reduces installation time and future electrical troubleshooting without moving to more complex multi-function connectors.