CURT USCAR-to-7-Way & 4-Way Wiring Adapter 55774 — Dual-Output, Plug‑In OEM Fit with Mounting Bracket

The CURT 55774 is a factory-side, plug-and-play wiring adapter that converts a USCAR tow socket into both a 7-way RV blade and a 4-way flat trailer connector without cutting or splicing.

Many late-model vehicles include a factory-installed USCAR tow socket intended to accept custom wiring adapters. The CURT 55774 takes advantage of that factory provision: it plugs into the vehicle’s OEM USCAR tow plug and provides two common trailer connectors—one 7-way for RV-style functions and one 4-way flat for basic lighting—so you can tow or connect accessories without altering factory wiring. It ships with a mounting bracket and dust covers for durability and convenience.

How does this adapter make trailer wiring easier?

The CURT 55774 eliminates cutting, splicing, and soldering by using the vehicle’s existing USCAR factory tow socket. Installation is typically a simple plug-in, and the dual outputs let you connect a wide range of trailers and tow equipment without swapping connectors.

• Plug-and-play design uses the OEM USCAR socket—no wire modification needed
• Dual outputs: one 4-way flat and one 7-way RV blade for versatile connections
• Includes mounting bracket for secure, tidy installation
• Protective dust covers keep contacts clean when not in use

What vehicle features are required for the CURT 55774 to work?

This adapter is designed specifically for vehicles equipped with a factory-installed USCAR tow plug (often part of a manufacturer tow package). If your vehicle lacks that OEM socket, this unit will not have a place to plug in and a different wiring solution will be required.

• Requires an OEM USCAR-style factory tow connector on the vehicle
• Often sold as an accessory when a factory tow package is present
• Confirm vehicle fitment using application details before purchase
• Not a universal splice harness—fits only USCAR-equipped vehicles

Which trailer functions are available from the 4-way and 7-way outputs?

The 4-way flat output supplies basic lighting signals—tail, brake, and turn—while the 7-way RV blade adds auxiliary circuits used by many trailers and RVs, including electric brakes, reverse/backup light feed (if wired), and a power/ground circuit for trailer accessories.

• 4-way flat: tail lights, brake lights, left/right turn signals
• 7-way blade: adds electric brake controller feed and auxiliary power/ground
• Enables use of trailers that require supplemental braking or power connections
• Both sockets available simultaneously for convenience

How durable and user-friendly is the CURT 55774?

CURT designs custom wiring connectors to withstand regular towing use while remaining simple to install. The included dust covers protect contacts from dirt and moisture, and the mounting bracket helps keep the connectors secure and accessible.

• Robust molded housings resist everyday wear and exposure
• Dust covers protect electrical contacts when unused
• Mounting bracket included for a secure, factory-like fitment
• No soldering or splicing required—reduces installation time and error risk

Who is this for: The CURT 55774 is ideal for vehicle owners who already have a factory USCAR tow socket and want the convenience of both 4-way and 7-way trailer connections without altering the factory wiring. It suits drivers who tow occasionally or regularly, owners of trailers that need auxiliary circuits or electric brakes, and installers who prefer a reliable, OEM-style plug-in solution. Before purchasing, verify that your vehicle’s tow package includes the appropriate USCAR connector to ensure compatibility.