Oyviny 4-Way Trailer Wiring Harness 55540 for 2003–2023 Chevy Express & GMC Savana — Plug-and-Play, Corrosion-Resistant

The Oyviny 4-way trailer wiring harness 55540 lets you add a standard 4-flat connector to compatible Chevy Express and GMC Savana models quickly and without cutting factory wiring.

If you tow trailers with lights, adding the right connector is essential for safe, street-legal towing. The Oyviny 55540 is designed to plug into the OE sockets on many 2003–2023 Chevrolet Express and GMC Savana trucks and vans, giving you reliable power for tail lights, turn signals and brake lights without splicing into the vehicle harness. Built with durable materials, corrosion-resistant contacts and a protective sleeve, the harness aims to simplify installation and stand up to road use.

Which vehicles is this harness compatible with?

The Oyviny 55540 is made specifically to fit a range of Chevy Express and GMC Savana models across multiple years. It covers both 1500 and 2500/3500 series in the model years listed, matching factory wiring locations for a plug-and-play connection.

• 2003–2014 Chevrolet Express 1500
• 2003–2023 Chevrolet Express 2500 and 3500
• 2003–2014 GMC Savana 1500
• 2003–2023 GMC Savana 2500 and 3500

How does installation work and how long does it take?

Installation is designed to be straightforward: the harness plugs into existing vehicle connectors and provides a 4-flat socket for the trailer plug. There’s no cutting or splicing required, so most users can complete the job with basic hand tools in a short timeframe.

• Ready-to-plug factory-style connectors — no wire splicing.
• About 80 inches of wire for flexible routing and mounting options.
• Includes a rubber dust cover to protect the socket when not in use.
• Typical install time: under an hour for a basic plug-in setup.

What materials and protections does the harness include?

The Oyviny harness uses materials chosen for conductivity and durability to withstand towing conditions. The connector body, wiring and protective sleeve are intended to resist abrasion and outdoor exposure.

• ABS plastic connector housing for impact resistance.
• Pure copper conductors for dependable electrical flow.
• Black nylon braided sleeve to shield wires from chafing.
• Corrosion-resistant 4-pin flat contacts plus a dust cover for moisture protection.

What trailer lighting functions will this support?

The standard 4-flat design supplies the basic lighting signals required for most small trailers. It routes vehicle signals to the trailer without adding auxiliary or electronic brake functions.

• Tail and marker lights lighting feed
• Left and right turn signals
• Brake light signal shared with turn circuits
• Not intended for electric trailer brakes or 7-pin auxiliary circuits

Who this is for: The Oyviny 55540 harness is aimed at Chevy Express and GMC Savana owners who need a clean, factory-style 4-flat trailer connection without permanently modifying their vehicle wiring. It’s a good match for van and truck owners towing utility trailers, boat trailers, small equipment haulers or light cargo trailers that require standard lighting signals. If you need electric brake control or additional power circuits, consider a compatible 7-pin solution, but for basic and reliable trailer lighting, this plug-and-play harness streamlines installation and protects vehicle wiring for regular towing use.