CURT 4-Way Trailer Wiring Harness for Chevrolet & GMC Pickups — Vehicle-Side 55315, Plug-and-Play with Dust Cover

CURT 55315 is a vehicle-specific, plug-and-play 4-way trailer wiring harness that adds a standard 4-pin connector to compatible Chevrolet and GMC pickup trucks without cutting or splicing.

If your pickup lacks a factory trailer plug, the CURT 55315 T-connector provides a factory-style electrical hookup for tail lights, turn signals and brake lights so you can tow safely and legally. Designed to mate with the OEM taillight sockets on select GMC C1500, C2500, C3500 and K1500, K2500, K3500 models, this harness installs quickly using the vehicle's existing wiring and includes a dust cover for long-term protection.

How does this harness install and how long will it take?

Installation is straightforward because the CURT 55315 is built to plug into your truck's factory taillight connectors — no cutting, splicing, or soldering required. Typical install time is short: many owners complete the job in 20–45 minutes using basic hand tools.

• Plug-and-play T-connector design matches OEM sockets
• No wire modifications or vehicle wiring changes
• Includes mounting hardware and straightforward routing
• Quick-release ergonomic connector tabs for easy hookup

What trailer functions does the CURT 55315 provide?

This harness supplies a standard 4-way flat trailer connector, delivering left/right turn signals, running lights and brake lights from your vehicle to the trailer. It’s ideal for lightweight trailers, utility trailers, and many small boats or cargo trailers that use a 4-pin wiring configuration.

• Left and right turn signal transmission
• Brake light output synchronized with vehicle brakes
• Tail/running light power for nighttime visibility
• Compatible with common 4-flat trailer plugs and adapters

Will this fit my truck and what’s included in the kit?

The CURT 55315 is vehicle-specific and engineered for select years of GMC C1500/C2500/C3500 and K1500/K2500/K3500 models — always verify compatibility with the application guide for exact fitment. The kit contains everything needed to establish a reliable trailer connection and protect the plug from weather when not in use.

• Vehicle-matched OEM-compatible taillight connectors
• 4-way flat female socket with ergonomic grip tabs
• Rubber dust cover to keep contacts clean and dry
• All mounting and wiring components for a complete install

How durable is the wiring for outdoor and towing use?

CURT designs this harness for long-term towing exposure with weather-resistant materials and a protective dust cap to keep the connector free of dirt and moisture. Proper routing and secure mounting help prevent abrasion and strain on the wiring during regular use.

• Weather-resistant connector housing and contacts
• Included dust cover for protection when unplugged
• Robust insulation and strain relief at connection points
• OEM-style fit reduces stress and prevents chafing

Who is this for? Drivers of compatible Chevrolet or GMC pickup trucks who need a fast, reliable way to add a standard 4-pin trailer connector without altering factory wiring will benefit most from the CURT 55315 harness. It’s ideal for weekend boaters, contractors using light trailers, and anyone who wants a neat, OEM-style towing connection that installs quickly and protects the vehicle’s original wiring.