Seamaka 26FT Trailer Wiring Harness 4-Way Flat 5-Wire (16AWG) — Jacketed Cable with 2.5FT Ground

The Seamaka 26FT 4-Pin 5-Wire Trailer Wiring Harness is a jacketed, 16AWG 4-way flat cable with an extra ground lead built to rewire and restore trailer taillights, turn signals and brake lights.

This heavy-duty 26-foot harness combines a 4-way flat plug with five color-coded conductors and a separate 2.5-foot ground to simplify trailer rewiring on boats, RVs, horse trailers and utility trailers. The PVC-sheathed cable protects copper conductors for long service life and reliable electrical connection across harsh conditions. It’s designed for easy installation and compatibility with standard 4-way flat trailer sockets.

How does this harness make trailer wiring easier?

Color-coded conductors and a pre-assembled 4-way flat plug reduce guesswork and installation time. The separate ground lead gives a secure chassis connection without splicing into existing wiring, and the long 26-foot run helps route the cable neatly along frames or through conduits.

• 26-foot main cable plus 2.5-foot ground for flexible routing
• 4-way flat plug pre-attached for quick connection
• Color-coded wires match standard trailer wiring conventions
• Leather-thick PVC jacket resists abrasion and weather

Is the cable durable enough for marine or off-road use?

The harness uses copper conductors wrapped in a thick PVC outer sheath that resists moisture, salt spray and abrasion. The rated 16AWG conductors and insulation tolerate a wide temperature range, making the set suitable for marine, agricultural and outdoor trailering environments.

• 16AWG copper wiring for reliable conductivity
• PVC insulation withstands cold and heat (-22°F to 221°F range)
• Jacketed construction protects against chafing and exposure
• Robust connectors designed for repeated mating cycles

What vehicles and trailers is this wiring kit compatible with?

Designed for any trailer system that uses a standard 4-way flat plug, the Seamaka harness fits utility trailers, boat trailers, RV tow vehicles, ATV haulers and horse trailers. It supplies power for tail, turn and brake lights while providing a reliable ground path via the separate lead.

• Works with 4-way flat trailer sockets on trucks and tow vehicles
• Commonly used on boat, utility, horse, ATV and cargo trailers
• Ideal for replacing worn wiring or installing a new plug
• Perfect when additional cable length is required

Who is this for?

This harness is aimed at DIYers, fleet maintenance technicians and boat or RV owners who need a durable, ready-made 4-way wiring solution. If you’re rewiring a trailer lamp circuit, replacing a corroded plug, or extending existing wiring to a new connector location, the Seamaka 26FT 4-Pin 5-Wire Harness provides a straightforward, weather-resistant option that reduces installation time and improves electrical reliability.