CURT vehicle-side 4-pin trailer wiring harness — Grand Highlander fit, plug-in OEM-style 4-way flat, no splicing

CURT 56524 is a vehicle‑side, plug‑in 4‑pin trailer wiring harness engineered to give select Toyota, Grand Highlander and Lexus TX models a clean, OEM‑style 4‑way flat trailer connection without cutting or splicing vehicle wiring.

If you need a reliable, factory‑like trailer connector for towing small to medium trailers, this CURT custom wiring connector plugs into an existing OEM socket and provides a durable 4‑way flat output for tail lights, brake lights and turn signals. It’s built specifically to fit certain years and trims of the Toyota Highlander, Grand Highlander and Lexus TX series, so installation is straightforward and reversible. The harness includes the necessary mounting hardware and a dust cover to protect the socket when not in use.

How does this harness simplify installation?

The CURT 56524 uses a vehicle‑specific OEM‑compatible plug so you don’t need to splice, cut or solder into the factory wiring. It’s essentially plug‑and‑play: line up the connector, insert into the factory socket, and secure with the supplied hardware. That reduces installation time and preserves your vehicle’s original wiring integrity.

• Direct OEM‑style plug fits the vehicle’s factory socket
• No splicing or modifications to factory wiring required
• Includes mounting hardware for a tidy, secure install
• Dust cover protects the connector when unused

What trailer lighting functions does the 4‑way flat support?

The 4‑way flat output provides standard trailer lighting circuits so your trailer’s tail lights, brake lights and turn signals operate in sync with the tow vehicle. This harness converts the vehicle signals into the universal 4‑pin format used by most small trailers and utility equipment.

• Left and right turn signals pass through to the trailer
• Brake lights synchronized with vehicle brake lamp output
• Running/tail lights powered for night and daytime visibility
• Compatible with most 4‑way flat trailer plugs and adapters

What durability and compatibility features ensure reliable performance?

CURT designs this custom connector with SMT circuitry and industry‑grade components to handle automotive environments. The vehicle‑specific design eliminates loose wiring, and the included dust cover helps prevent corrosion and debris buildup when the socket is not in use. Always check the application list to confirm vehicle compatibility before purchase.

• Surface‑mount (SMT) circuitry for stable electrical performance
• Sealed connector housing and dust cover for corrosion resistance
• Factory‑fit shape and locking mechanism for a secure connection
• Tested by CURT for consistent, dependable operation

Will this harness work with my specific Highlander or Lexus model?

The 56524 is made for select years and trims of Toyota Highlander, Grand Highlander and Lexus TX models. Because vehicle wiring and sockets vary by production year and trim, verify compatibility using the CURT application guide or your vehicle’s fitment information before ordering. Installing an incompatible connector may prevent a proper fit.

• Designed for specific Toyota Highlander and Grand Highlander years and Lexus TX trims
• Reference CURT’s application chart or the product listing fitment tool
• Professional installers can confirm socket type if uncertain
• Return or exchange if fitment guidance indicates mismatch

Who is this for: Drivers who tow small trailers, utility carts, or recreational equipment from compatible Toyota and Lexus vehicles and want a clean, reversible, OEM‑style trailer wiring connection. It’s ideal for owners who prefer a plug‑and‑play solution that preserves factory wiring, reduces installation time, and provides a protected 4‑way flat socket ready for everyday towing use.