Oyviny 4-Pin Trailer Wiring Harness 56325 for GMC Acadia/Cadillac XT5 XT6 — 77" Plug-and-Play 4-Flat with Dust Cover

The Oyviny Custom 4 Pin Trailer Wiring Harness 56325 is a plug-and-play trailer connector that adds a weather-resistant 4-flat outlet to compatible GMC, Cadillac, Chevy and Buick SUVs without cutting or splicing.

If you need a reliable, vehicle-specific 4-way trailer connection for towing lights and turn signals, this harness is built to mate with the factory tow package on select model years of GMC Acadia, Cadillac XT5/XT6, Chevy Blazer and Buick Envision. It provides a full-size 4-flat plug, 77 inches of heavy-duty wiring, tin-plated copper terminals and a protective dust cover so you can tow trailers, bike racks, or cargo carriers with a standardized signal hookup.

Will this harness fit my vehicle?

The Oyviny 56325 harness is designed as a direct fit for specific model years and plugs into the OEM tow wiring harness without modification. Confirm compatibility by checking your vehicle’s model year and the presence of the factory tow package plug under the rear bumper.

• Compatible models: GMC Acadia 2017–2023, Cadillac XT5 2017–2025, Cadillac XT6 2020–2025
• Also fits: Chevy Blazer 2019–2025, Buick Envision 2021–2025
• No cutting or splicing: installs into the vehicle’s original connector
• Designed for vehicles with an OEM tow harness receptacle

How do I install the Oyviny 4-way connector?

Installation is straightforward: locate the factory tow harness behind the rear bumper, unplug the vehicle’s connector, and mate the Oyviny harness to that OEM plug. The harness comes ready to plug in, so you won’t need special tools or wire taps for most installations.

• Ready-to-plug harness — no cutting, splicing, or wire stripping required
• 77-inch lead gives room to route and secure wiring behind trim panels
• Dust cover helps keep the socket clean when not connected to a trailer
• Simple reversing of steps restores the factory harness if removed

What are the construction and performance features?

This harness uses 16 AWG bonded pure copper conductors for dependable signal transmission and low resistance. The 4-flat plug and terminals are tin-plated to resist corrosion, and the connector has a rubber dust cap to shield contacts from moisture and dirt when the trailer isn’t connected.

• 16 AWG bonded pure copper wires for robust conductivity
• Tin-plated copper terminals reduce corrosion and improve longevity
• Corrosion-resistant 4-flat connector with rubber dust cover
• 77" cable length provides flexibility for routing and mounting

What can I expect when using this harness with my trailer?

The Oyviny 4-way provides the standard trailer lighting circuits: running lights, left and right turn signals, and brake lights. It’s intended for signal connections only and works with a wide range of trailers that use the 4-flat standard.

• Supports tail lights, brake lights and turn signals on 4-flat trailers
• Compatible with most light-duty trailers, cargo carriers, and bike racks
• Not a braking control or power feed — for signal circuits only
• Easy to inspect and disconnect thanks to the standard flat plug

Who is this for: The Oyviny 56325 harness is aimed at owners of compatible GMC, Cadillac, Chevy and Buick SUVs who want a clean, factory-style 4-way trailer outlet without modifying factory wiring. It's ideal for weekend trailers, light towing tasks, and anyone seeking a durable, plug-and-play solution that preserves OEM wiring integrity.