WALSIO 4-Pin 5-Wire Trailer Wiring Harness — 22ft Y-Harness with Colour‑Coded Wires & Weatherproof Plug

WALSIO's 4-pin, 5-wire 22ft trailer wiring harness is a ready-to-install Y-harness that replaces worn 4-way connectors and provides extra ground and length for clean, reliable trailer wiring.

This all-in-one kit is built for straightforward trailer rewiring and replacement jobs. It combines a male 4-way flat plug, color-coded 18 AWG copper conductors, a protective braided jacket and a Y-shaped split so you can route wires without crossing the axle. Weatherproof covers and heavy PVC insulation make it suitable for open trailers, boat trailers and utility applications where durability matters.

How does this harness simplify replacing a worn 4-way trailer plug?

Instead of reusing shaky splices or hunting for multiple components, the WALSIO harness gives you a single assembly that matches industry-standard 4-way flat sockets. Color-coded wires reduce guesswork during hook-up and the included male plug fits most trailer receptacles without modification.

• Direct 4-way male plug ready for common trailer sockets
• Color-coded conductors for easy identification and hookup
• Preassembled 22ft length avoids buying extra wire or extensions

What makes the Y-harness layout useful for trailer wiring?

The integrated Y-split lets you run separate legs to each trailer side without routing a wire across the axle, limiting exposure and reducing chafing risk. This layout speeds installation and produces a neater, safer routing for lights and ground connections.

• Y-shaped split placed toward the front for cleaner routing
• Eliminates need to run a single wire across the axle
• Simplifies left/right light and ground distribution

Are the materials and connectors durable enough for outdoor use?

Yes—WALSIO uses 18 AWG pure copper conductors for consistent conductivity, thick PVC jacketing for insulation, and an outer braided nylon sleeve for abrasion resistance. The male plug includes a protective cover to keep out water and dust when disconnected.

• 18 AWG pure copper for reliable electrical performance
• Thick PVC coating plus braided nylon outer sleeve for protection
• Weatherproof plug cover to reduce corrosion and moisture intrusion

How long is the harness and what trailer types is it suitable for?

The overall harness measures 22 feet with an additional 2.5-foot ground leg, giving ample slack for many trailer geometries. It fits trailers up to and beyond 80 inches in width and is compatible with boat, utility, ATV and horse trailers using 4-way flat connections.

• 22ft total length with 2.5ft ground wire for flexible routing
• Designed to fit trailers around 80 inches wide and larger
• Works with common trailer types that use 4-way flat connectors

Who this is for: installers, hobbyist DIYers and fleet managers who need a dependable, preassembled replacement harness that reduces installation time and minimizes wiring mistakes. If you want a weather-resistant, color-coded Y-harness that avoids running a wire across the axle and fits standard 4-way flat sockets, this WALSIO kit is built to make rewiring faster and cleaner without extra parts.