Oyviny 4‑Pin Trailer Wiring Harness for Toyota Highlander 2004–2007 — Plug‑and‑Play with Powered Module & Pure Copper

The Oyviny 56107 is a custom 4‑pin trailer wiring harness that adds a durable, plug‑and‑play 4‑way connector to 2004–2007 Toyota Highlander models equipped with the factory tow package.

If you own a 2004, 2005, 2006 or 2007 Toyota Highlander with the factory tow package and need a reliable way to power trailer tail lights, turn signals and brake lights, this harness provides a direct, vehicle‑specific solution. Designed to match factory connectors and avoid wire splicing, the Oyviny 56107 installs quickly while protecting your vehicle’s electrical system with a powered module and in‑line fuse.

How does this harness connect to my Highlander without splicing?

The Oyviny 56107 uses custom‑molded connectors that mate with the Highlander’s factory tow package plugs, so you simply unplug the original connection and plug in the harness. No cutting, tapping, or soldering is required—making installation fast and reversible.

• Vehicle‑specific plug ends for exact fit
• Plug‑and‑play design eliminates wire splicing
• Includes battery feed via powered module to protect vehicle circuits

What signals and lights will this 4‑pin connector support?

This 4‑pin flat connector supplies the standard trailer lighting signals: running/taillights, left and right turn signals, and an integrated brake/turn feed depending on trailer wiring. It’s intended for trailers that don’t require a dedicated brake controller or auxiliary power circuits.

• Taillight and running light feed
• Left and right turn signal output
• Compatible with most 4‑pin trailers and light‑only loads

What materials and protections does the harness include?

Oyviny built the 56107 with longevity in mind: 16 AWG pure copper conductors inside durable ABS molded connectors for consistent conductivity and corrosion resistance. Critical components such as the flat connector and the inline fuse are covered with rubber dust caps to keep out moisture and dirt.

• 16 AWG bonded pure copper wiring for reliable conductivity
• ABS plastic connectors resistant to impacts and weathering
• Rubber dust caps for connector and fuse to prevent corrosion and shorts

Will this wiring harness overload my Highlander’s electrical system?

No. The harness includes a powered module that draws directly from the battery and an in‑line fuse to limit current, so trailer lighting loads don’t run through sensitive vehicle circuits. This reduces the chance of blown fuses or electrical faults in the factory harness.

• Battery‑fed module prevents excessive load on factory wiring
• In‑line fuse protects wiring from short circuits and overloads
• Designed to meet typical trailer lighting current requirements

Who is this for? The Oyviny 56107 wiring harness is intended for Toyota Highlander owners (model years 2004–2007) who have the factory tow package and want a quick, factory‑style way to add a 4‑pin trailer connector. It’s well suited for drivers hauling small utility trailers, boat trailers with separate brake systems, or anyone needing a dependable, corrosion‑resistant trailer light connection without altering factory wiring. If your trailer requires 5‑pin or 7‑pin functions (electric brakes, auxiliary power), consider a different harness or adapter that includes those circuits; otherwise, this harness provides a clean, vehicle‑matched installation for standard trailer lights.