Towing a trailer starts with a solid electrical connection, and the CURT 56291 custom-fit wiring connector makes that connection the right way. Designed to plug directly into your vehicle's existing factory harness without cutting, splicing, or tapping wires, this harness delivers a reliable 4-pin flat output at the rear of your vehicle so your trailer's running lights, brake lights, and turn signals work exactly as they should.
The CURT 56291 is part of CURT's T-connector custom wiring family -- vehicle-specific harnesses engineered to mate with the factory tail light wiring on select cars, trucks, SUVs, and minivans. Unlike universal splice kits that require you to cut into your vehicle's wiring, the 56291 uses a T-one connector design: it taps into existing tail light circuits by unplugging the factory connector, inserting the T-harness in line, and plugging everything back together. No splicing. No guesswork. No voided warranties from hacked wiring.
The output is a standard 4-pin flat connector, the most common trailer wiring format in North America. It carries the four basic functions -- left turn/brake, right turn/brake, tail/running lights, and ground -- which covers the vast majority of single-axle utility trailers, boat trailers, landscape trailers, and small enclosed cargo trailers.
Plugs inline with factory tail light connectors. No wire cutting, no crimping, no electrical tape. Maintains OEM wiring integrity.
Standard North American trailer connector format. Compatible with the vast majority of utility, boat, and cargo trailers sold today.
Custom molded connectors match factory plugs on select vehicles. No adapter needed -- it either fits or it does not.
Built-in protection prevents trailer wiring faults from feeding back into the vehicle's electrical system -- critical on modern CAN-bus equipped tow vehicles.
Modern vehicles -- especially those with LED tail lights, load-sensing circuits, or body control modules -- are very sensitive to electrical interference. Splicing or tapping directly into the tail light wires can trigger fault codes, cause flickering, or blow fuses. CURT's T-one style harnesses solve this by using a converter module that reads the existing tail light signals and outputs them to the 4-pin flat in a way the vehicle does not detect as a fault.
The converter in the CURT 56291 harness is typically a small sealed module that mounts out of sight behind the bumper or under the cargo floor. The harness routing keeps everything tucked away and weather-resistant once installed.
Because the 56291 plugs into existing factory connectors, there is nothing for a future buyer -- or your dealer -- to spot as an aftermarket modification. Your tail light wiring remains untouched and fully reversible.
This 4-function setup covers all legally required lighting on trailers under 80 inches wide. If you are towing a trailer that also needs electric brakes or a 12V auxiliary circuit, you would need to step up to a 5-pin or 7-pin connector -- but for most utility, boat, and small cargo trailers, 4-pin flat is the correct choice.
4-pin flat handles running lights, turn signals, and brake lights -- all you need for non-brake-equipped trailers. If your trailer has electric brakes, a breakaway battery, or a 12V power circuit, look for a CURT 5-pin or 7-pin connector instead. The 56291 is the right fit for light-duty trailers without electric brakes.
Installation is typically 15 to 30 minutes with basic hand tools. The general process for CURT T-one connectors like the 56291:
CURT assigns specific part numbers to specific vehicle applications within their custom wiring family. The 56291 is designed for a particular make/model/year combination -- the custom fitment is the entire point. CURT's wiring part numbers in the 56000-56999 range are vehicle-specific T-one connectors. If you are cross-shopping, confirm your vehicle year, make, model, and trim using CURT's online fit guide to ensure the 56291 matches your application before ordering.
CURT manufactures both trailer hitches and wiring harnesses designed to work together on specific vehicles. If you are also installing a new hitch receiver, check CURT's vehicle-specific hitch lineup to find the matched hitch and wiring combination for your tow vehicle for the cleanest overall install.