Oyviny 4-Pin 5-Wire Trailer Wiring Harness 50FT - Y-Wishbone Rewire, Pure Copper & Nylon Protection

The Oyviny 50FT 4-pin 5-wire trailer wiring harness is a Y-harness kit that lets you rewire both-side taillights and connect brake lights, turn signals and grounds with a single 4-way flat plug.

This wiring harness is built for straightforward trailer rewiring: a 50-foot male 4-flat cable with a 2.75-foot ground tail, color-coded conductors, pure copper cores, and a protective nylon net tube. The wishbone (Y) design splits the brown taillight feed so left and right lamps receive power simultaneously without extra splicing, while the standard 4-way flat plug fits industry sockets for easy replacement or installation.

How does the Y-harness design simplify trailer taillight wiring?

The Y-shaped wiring layout removes the need to run separate hot feeds for left and right taillights. One brown feed is split into two runs, saving time and reducing junctions that can corrode or fail.

• Single input splits to left and right taillight outputs to power both sides simultaneously.
• Color-coded wires match common trailer wiring conventions for easier splicing.
• Reduces the number of splices compared with two independent runs, improving reliability.

Will the length and connectors work for most trailers?

Yes — the 50-foot main cable gives ample reach from a trailer tongue to lights on large trailers, and the 2.75-foot ground tail helps you reach a chassis ground point. The male 4-way flat plug is made to industry standard dimensions to mate with common vehicle and trailer sockets.

• 50-foot main wire accommodates long trailer frames and flexible routing.
• 2.75-foot ground lead intended for convenient chassis grounding.
• Standard 4-flat male plug fits typical 4-way flat sockets for straightforward swaps.

What materials and protections extend the harness’ service life?

Oyviny uses pure copper conductors for consistent electrical conductivity and a thicker PVC jacket to resist abrasion and corrosion. The whole assembly is sheathed in a black nylon net tube that shields wires from chafing and UV exposure while allowing flexibility.

• Pure copper cores for dependable electrical flow and lower resistance.
• Thickened PVC insulation for water and abrasion resistance.
• Nylon net tube provides an extra protective layer against wear and environmental damage.

How do I install and match colors to my trailer wiring?

Installation is straightforward: route the harness along the frame, secure with clamps or zip ties, splice color-to-color to the trailer’s existing leads, and attach the ground. The cable uses standard color coding to identify function and minimize wiring errors.

• Match colored conductors to existing wires: brown (taillights), yellow/green (turn signals), white (ground), etc.
• Use heat-shrink, solder, or waterproof crimp connectors for durable splices.
• Secure harness with clips, then test each light function before finalizing installation.

Who this is for: The Oyviny 4-pin 5-wire 50FT harness is for DIY trailer owners, repair shops, and fleet managers who need a dependable, long-reach replacement or upgrade to power both taillights from a single 4-way flat connection. It suits utility trailers, boat trailers, RVs, and custom builds where reliable copper conductors, clear color coding, and extra protective sleeving make installation quicker and longer lasting.