Oyviny Brake Controller Wiring Adapter 3040 for Toyota & Lexus — 4‑Pin Plug, 31-inch Harness

The Oyviny 3040 Brake Controller Wiring Adapter is a plug-and-play 4-pin harness that lets compatible Toyota and select Lexus models accept aftermarket electric trailer brake controllers without cutting or splicing vehicle wiring.

If you tow trailers with electric brakes, installing a dedicated brake controller is often necessary for safe, controlled stops. The Oyviny 3040 harness is built to bridge many Toyota and Lexus models (Tundra, Tacoma, 4Runner, Sequoia, Land Cruiser and select GX/LX years) to popular third-party brake controllers, simplifying installation and protecting the vehicle’s original wiring.

Which vehicles and brake controllers work with this harness?

This adapter supports a range of Toyota model years and specific Lexus models—refer to the compatibility picture for exact year-by-year fit. It uses the industry-standard 4-pin brake controller connector so it pairs with many well-known brake controllers from Tekonsha, Draw-Tite and Reese.

• Fits: Toyota Tundra 2003–2014, Tacoma 2005–2015, 4Runner 2003–2013, Sequoia 2003–2022, Land Cruiser 2003–2021
• Select Lexus: GX460, GX470, LX470, LX570 (2003–2020 for select models)
• Compatible controllers: Tekonsha P2/P3/Prodigy, Draw-Tite Activator series, Reese Towpower models, and similar 4-pin units

How difficult is installation and what tools are needed?

Installation is straightforward because the adapter is designed to plug directly into the vehicle’s factory brake controller port and the controller’s 4-pin plug. No wire cutting, splicing, or special crimping is required, which reduces installation time and risk to factory wiring.

• Plug the harness into the brake controller, then into the factory port beneath the dash
• No soldering or wire modification needed—saves time and preserves factory wiring
• Basic tools like a flashlight or trim tool may help access the dash port

What are the construction and performance details of this adapter?

The harness combines durable ABS plastic plugs and tin-plated copper terminals for reliable electrical contact and corrosion resistance. A protective nylon net tube shields the wires and reduces abrasion, while the 31-inch length gives room to position the controller where it’s convenient for the driver.

• Materials: ABS plug bodies with tin-plated copper terminals for longevity
• Protection: Black nylon net tubing guards against wear and minor impacts
• Length: ~31 inches to allow flexible controller placement under the dash

Will using this adapter affect safety or vehicle electronics?

The adapter is intended to maintain factory wiring integrity by avoiding splices that can introduce shorts or poor connections. While it facilitates installing a compatible brake controller, you should still follow the brake controller maker’s setup and calibration procedures for safe operation.

• Maintains original harness integrity—no permanent vehicle wiring changes
• Reduces risk of cross-wiring and short circuits during installation
• Final brake control performance depends on the controller and proper setup

Who is this for: Drivers who tow trailers with electric brakes and own a compatible Toyota or select Lexus model, but want an easier, cleaner installation of an aftermarket brake controller. It's ideal for owners who prefer to avoid cutting factory wiring, installers seeking a time-saving harness, and anyone who wants a durable plug-and-play connection to well-known brake controller brands.