Stop worrying about cut wires and electrical gremlins. The CURT 56327 is a vehicle-specific, plug-and-play T-One wiring harness that integrates directly with your factory tail light circuit -- no splicing, no crimping, no guesswork. It delivers clean trailer lighting signals through a standard 4-flat connector so your tow vehicle and trailer communicate correctly every time you hook up.
The CURT 56327 belongs to CURT's T-One custom fit wiring harness family -- a lineup of vehicle-specific harnesses engineered to mate with the factory wiring on particular makes and models. Unlike universal splice-in kits that require you to cut into your vehicle's wiring loom, the T-One harness uses a T-connector that plugs in between your vehicle's existing tail light plugs. The factory circuit stays 100 percent intact.
The harness routes cleanly along the vehicle's existing wire paths and exits at the rear with a standard 4-flat connector (also called a 4-pin flat), which is the most common trailer connector type in North America. It supports running lights, brake lights, and turn signals -- the four circuits required for trailer towing under federal lighting standards.
T-connector plugs directly into the factory tail light harness. No wire cutting, no soldering, no electrical tape.
Standard 4-pin flat connector is compatible with the vast majority of trailers, boat trailers, utility trailers, and cargo carriers.
Engineered to match the exact plug configuration of the target vehicle -- no universal adapters or make-it-work wiring required.
Includes an integrated converter module where needed to reconcile LED or separate-function tail light systems with standard 4-flat trailer wiring.
Many modern vehicles use a combined function tail light system where a single bulb or LED cluster handles braking and turn signals together. Standard 4-flat trailer wiring requires separate brake and turn circuits. The T-One harness includes an integrated converter module that handles this translation automatically -- you do not need to buy a separate converter box.
Older vehicles with already-separate brake and turn circuits do not require conversion. In either case, the 56327 harness is built specifically for the target vehicle so the right solution is already built in from the factory.
This covers all federally required trailer lighting functions for trailers under 80 inches wide. If your trailer also requires electric brakes or a 12V auxiliary circuit, you will need a 5-flat, 6-flat, or 7-way connector system -- the 56327 is a 4-flat solution only.
Installation is straightforward for a DIYer with basic mechanical aptitude. General steps:
CURT Manufacturing is one of the largest trailer hitch and towing accessory brands in North America. Their T-One harness line covers hundreds of vehicle applications and is sold through major automotive and RV retail channels. The 56327 is a specific SKU within that broader T-One family, each assigned to a particular vehicle application. CURT harnesses are SAE-compliant and tested to work with the vehicle's onboard electrical system without triggering trailer-detection errors or BLIS/blind-spot system faults (on supported vehicles).