The CURT 56161 is a vehicle-specific T-One wiring connector that plugs directly into your existing tail light wiring harness to add a standard 4-flat trailer connector. No wire cutting, no splicing, no guesswork -- just a clean, factory-style installation that powers your trailer lights from your tow vehicle's existing brake, turn, and running light circuits.
CURT's T-One connector family is one of the most trusted names in vehicle-specific trailer wiring. The 56161 is engineered to match the factory tail light connector on specific vehicle applications, plugging inline between the vehicle's harness and the tail light socket. The connector passes through the original signals uninterrupted while adding a 4-flat trailer output.
Unlike universal wiring kits that require stripping wires and using T-taps, this connector uses OE-style plugs for a secure, vibration-resistant connection that won't degrade over time. It's the right solution for towing trailers, bike racks with lighting, cargo carriers, and small boat trailers that use the 4-flat (4-pin flat) standard.
Engineered to match OE tail light connectors on specific makes and models -- no universal adapter guesswork.
Plugs directly inline with factory wiring. No wire cutting, no T-taps, no risk of damaged circuits.
Delivers the industry-standard 4-pin flat connector used on the vast majority of utility, cargo, and small boat trailers.
Built-in circuit protection helps prevent damage from trailer wiring shorts or overload conditions.
The 4-flat (also called 4-pin flat or 4-wire flat) connector carries these four circuits:
This connector is not designed for electric brake control or 12V auxiliary power. It is a lighting-only harness. If your trailer has electric brakes or requires a 12V charge line, you will need a 5-flat, 6-flat, or 7-pin connector setup instead.
CURT manufactures hundreds of T-One connectors, each keyed to specific vehicle tail light plug configurations. The 56161 is one connector in this broad family. All T-One connectors share the same plug-in installation approach; what varies is the OE connector shape and pin count on the vehicle side. CURT provides application data by year, make, and model to confirm fitment before you buy.
Common vehicle types this connector family serves include SUVs, minivans, crossovers, and light trucks where the manufacturer uses a specific multi-pin tail light plug rather than exposed wire pigtails.
Most installations require no tools beyond a panel removal pry tool and take 20 to 45 minutes depending on vehicle access.