WALSIO 32ft Trailer Wiring Harness 4-Pin 5-Wire — Black Y‑Split Weatherproof, SAE J1128

WALSIO's 32-foot 4-pin 5-wire trailer wiring harness is a ready-to-install cable kit that provides full four-way trailer lighting plus a dedicated ground in a weatherproof, color-coded assembly.

This harness is made for owners who need a durable, long-reach replacement or factory-style wiring upgrade for trailers — boat trailers, ATVs, horse trailers and utility trailers. Built to SAE J1128 low-voltage cable standards, it combines 18 AWG pure copper conductors, thick PVC jacket, and an outer braided nylon sleeve for abrasion resistance. The kit includes a male 4‑way flat plug, a Y-style split to route wiring conveniently, and a 2.5 ft ground lead so you can complete the circuit without splicing or extensions.

How does this harness simplify trailer rewiring?

The WALSIO harness arrives pre-assembled with five color-coded conductors so you don’t have to run extra wires or guess connections. Its Y-harness layout positions the split near the trailer nose, avoiding runs across the axle and reducing strain points.

• Five wires cover tail, left/right turn, brake/stop, auxiliary, plus ground.
• Color-coded conductors match industry-standard 4-way connections for easy hookup.
• Y-shaped split allows routing down each side of the trailer without crossing the axle.
• Includes a 2.5 ft ground wire to ensure a reliable chassis return path.

Is this wiring durable enough for marine or heavy-duty use?

Yes — materials and construction focus on weather resistance and long life. The 18 AWG pure copper core provides good conductivity while the PVC jacket and braided nylon sleeve protect against abrasion, oil, and UV exposure.

• Meets SAE J1128 low-voltage primary cable standard for safety and performance.
• Thickened PVC outer coating resists moisture and chemicals.
• Black braided nylon mesh adds abrasion protection where the harness flexes most.
• Protective plug cover keeps contacts dry and dust-free when disconnected.

Will this fit my trailer and my vehicle's 4‑way flat socket?

The WALSIO kit is designed to mate with the common 4-way flat connectors used on most trucks and trailers. At 32 feet overall length, it's long enough for larger trailers and offers placement flexibility for routing and mounting.

• Compatible with standard 4-way flat trailer sockets and four-function systems.
• 32 ft total length accommodates trailers up to and beyond 100 inches in width with flexible routing.
• Male 4-way flat plug included for replacement installations.
• Color-coding reduces installation errors and speeds system testing.

How easy is installation for non-professionals?

The harness is built for straightforward DIY replacement: wires are color-coded and labeled by function, and the Y-configuration removes the need to run wiring across the trailer axle. Basic hand tools and the included instructions are typically all that’s required.

• Color-coded wires correspond to standard trailer lighting functions for intuitive hookup.
• Pre-terminated 4‑way male plug eliminates crimping to the vehicle connector.
• Y-harness design reduces complex routing and splicing across the axle.
• Instruction manual included for step-by-step guidance.

Who this is for: The WALSIO 32FT 4-Pin 5-Wire Trailer Wiring Harness is aimed at trailer owners and DIY mechanics who want a reliable, long-length wiring solution without complicated splices or adaptor chains. It suits users replacing worn or damaged 4‑way systems, outfitting larger trailers that need extra reach and a dedicated ground, and anyone who wants a durable, weather-resistant wiring assembly built to automotive low-voltage standards. If you need a straightforward, weatherproof harness that pairs with common 4-way flat sockets and reduces routing hassles, this kit is a practical choice.