CURT 57672 Trailer Wiring Adapter 4-Way to 7-Way RV Blade, Dual-Output Black, Weather-Resistant

CURT 57672 is a dual-output trailer wiring adapter that converts a vehicle's 4-way flat socket into both a 4-way flat and a 7-way RV blade outlet, giving you the flexibility to tow a variety of trailers with minimal wiring.

Mix-and-match trailer connections are common when you own multiple trailers or borrow a trailer with a different plug than your tow vehicle. The CURT 57672 adapter solves this by providing a ready-to-install 4-pin to dual-output wiring interface that preserves your existing 4-way flat function while adding a standard 7-way RV blade socket. The unit is built with weather protection, a mounting bracket and basic hardware to make installation straightforward for anyone comfortable with light splicing and vehicle electrical work.

How does this adapter let me tow trailers with different plugs?

The CURT 57672 accepts power from your vehicle's 4-way flat socket and routes those circuits to two outputs: a retained 4-way flat output and an added 7-way RV blade receptacle. It keeps essential circuits active and provides terminals for additional functions like reverse lights, brakes, and auxiliary power when you splice the necessary wires.

• Plugs directly into a standard 4-way flat vehicle socket
• Provides both 4-way flat and 7-way RV blade outputs simultaneously
• Requires limited manual wiring or splicing for extra functions

What weather protection and durability features does it include?

This adapter is designed for outdoor use and tow conditions, with dust covers to shield the terminals from moisture and contaminants. The main housing is molded black plastic that resists rust and corrosion, and the wiring bundle is routed through a slit loom sleeve to reduce abrasion and exposure.

• Dust covers for both 4-pin and 7-pin sockets to keep terminals clean
• Durable plastic housing that won’t corrode like metal
• Included slit loom sleeve to protect wiring from chafing

How difficult is installation and what comes in the kit?

Installation is intended to be simple for users familiar with trailer wiring basics. The adapter plugs into your vehicle's 4-way flat, and the kit includes a mounting bracket and hardware for securing the unit near the hitch. Some splicing is necessary if you need full 7-way functionality beyond basic lights.

• Ready-to-plug 4-way input reduces initial wiring work
• Mounting bracket and hardware included for tidy attachment
• Some manual splicing required for trailer brakes, reverse, or aux power

Which trailer functions can I expect to support with this adapter?

The adapter supports the core lighting circuits out-of-the-box and offers terminals to extend service to reverse lights, electric brakes, and auxiliary power. Exact features available will depend on how you wire the 7-way blade output and the equipment on your trailer.

• Taillights, brake lights and turn signals via standard circuits
• Provision for trailer brakes and reverse lighting with splicing
• Auxiliary 12V power available when properly connected

Who is this for: The CURT 57672 is aimed at vehicle owners who tow different trailers or occasionally connect to a trailer with a 7-way blade plug while their vehicle has only a 4-way flat socket. It’s a practical solution for DIYers, fleet vehicles, RV owners who switch trailers, and anyone seeking a durable, weather-resistant way to expand towing compatibility without installing a full factory 7-way harness. If you need a permanent factory-style install or prefer plug-and-play trailer brake control, consult a professional installer to evaluate if a full 7-way conversion is more appropriate.