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Curt 56274 Custom Fit Trailer Wiring Harness - Vehicle-Specific T-Connector

CURT 56274 Custom Fit Trailer Wiring Harness T-Connector, vehicle-specific plug-in design for 4-flat trailer lighting output
 
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: $111.46
Part Number: 56274
Manufacturer: Curt MFG

Quantity in Stock :40

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CURT Manufacturing Part 56274 No-Splice Install CURT 56274 Custom Fit Trailer Wiring Harness -- Vehicle-Specific T-Connector

Stop wrestling with universal wiring kits that require cutting and splicing your factory harness. The CURT 56274 is a vehicle-specific T-connector harness engineered to plug directly into your vehicle's existing tail light wiring, delivering a clean 4-flat output for trailer brake lights, turn signals, and running lights -- no electrical tape, no butt connectors, no warranty headaches.

Plug-In Trailer Wiring Done Right

CURT's custom fit wiring harnesses are designed to match the exact connector configuration of a specific vehicle year, make, and model. The 56274 uses CURT's T-One connector approach: one end plugs into the factory tail light socket, the other receives the original factory bulb, and a third pigtail outputs to a standard 4-flat trailer connector. The vehicle's own wiring does the heavy lifting -- no tapping, no splicing, no risk of blowing a fuse or triggering a check-engine light from a poorly joined ground.

CURT harnesses in this family are SAE-compliant and designed to work with the factory lighting circuit's existing load. They are passive connectors -- they do not include a brake controller, surge protector, or converter module. If your tow vehicle uses LED tail lights and you are towing a trailer with incandescent lamps (or vice versa), verify load compatibility before purchase; some pairings may require an add-on converter.

No-Splice Design

Plugs directly into factory tail light sockets. Zero cutting into OEM wiring. Preserves factory warranty and circuit integrity.

4-Flat Output

Standard 4-wire flat trailer connector output -- compatible with virtually all light-duty trailers, utility trailers, boat trailers, and cargo trailers.

Vehicle-Specific Fit

Engineered for a precise year/make/model application. No adapter fumbling, no universal guesswork -- connectors mate the first time.

Compact Package

Ships at 1.46 lbs in a 9 x 6 x 3 inch box. Everything needed for a complete install is included in a single tidy kit.

How the T-Connector System Works

CURT's T-One connector concept is one of the cleanest approaches to trailer wiring in the aftermarket. The harness literally intercepts the tail light circuit at the bulb socket -- you unplug the factory connector, plug in the CURT harness, and the original bulb plugs back into the pass-through on the harness. The 4-flat pigtail exits the rear bumper area and stows away when not towing. Install time on most vehicles is under 30 minutes with basic hand tools.

Because the harness is custom-made for a specific vehicle, the wire lengths are cut to reach each tail light location without excess slack bunching up in the trunk or cargo area -- a detail universal kits consistently get wrong.

Clean Factory-Style Installation
The T-connector approach means there is nothing permanently altered on your vehicle. If you sell the vehicle or remove the trailer hitch, the wiring harness unplugs and leaves zero trace. Ideal for leased vehicles or late-model trucks and SUVs where you want to protect factory wiring.

What Signals Are Passed Through

The 4-flat connector carries the four standard lighting functions required by federal law for trailers operated on US roads:

  • Left turn / brake signal -- yellow wire on 4-flat
  • Right turn / brake signal -- green wire on 4-flat
  • Tail / running lights -- brown wire on 4-flat
  • Ground -- white wire on 4-flat

This harness does not carry a dedicated brake controller output (blue wire), a 12V accessory circuit (red wire), or a backup light signal. For those functions, a 5-flat or 7-way connector system and separate wiring are required.

4-Flat vs. 7-Way -- Know Your Trailer's Needs
The 4-flat connector on this harness is correct for most utility, boat, and landscape trailers with basic lighting only. If your trailer has electric brakes, a breakaway system, or 12V accessories (like a refrigerator or power jack), you will need a 7-way connector system instead. Check your trailer's plug type before ordering.

Typical Compatible Applications

CURT part 56274 is a vehicle-specific harness. Based on CURT's product family structure, this part number fits a defined set of vehicle year/make/model combinations. Common application categories for CURT 5627x-series harnesses include late-model domestic SUVs, crossovers, and pickup trucks. Verify your exact vehicle fitment using CURT's online vehicle selector or the fitment data on the product listing before ordering.

Confirm Your Vehicle Fitment Before Purchase
This is a vehicle-specific part. Ordering the wrong harness is the single most common installation mistake. Double-check year, make, model, and trim level -- some vehicles use different tail light configurations by trim or production date.

Installation Tips

Fast, Clean Install -- Follow These Steps
  • Turn off the vehicle and disconnect the battery if your vehicle's manual recommends it for tail light work.
  • Access the tail light assemblies from inside the cargo area or trunk -- most applications do not require removing exterior lenses.
  • Unplug the factory connector from each tail light, plug in the CURT harness connector, and plug the factory bulb socket into the pass-through port.
  • Route the 4-flat pigtail along the bumper or frame rail and secure with the included cable ties. Keep it away from exhaust.
  • Test all four trailer circuits with a circuit tester or a known-good trailer before your first tow.

Trailer Types This Harness Supports

  • Open utility trailers
  • Enclosed cargo trailers (with basic 4-wire lighting)
  • Boat trailers
  • Landscape and lawn equipment trailers
  • Small camper trailers without electric brakes
  • Motorcycle and ATV trailers
Complete Your Towing Setup
Pair this wiring harness with a CURT receiver hitch and a ball mount sized for your trailer coupler height. CURT's T2 and T3 hitch balls, trailer safety chains, and trailer connector extensions are all designed to work alongside this harness for a complete, matched towing system.

Package Specifications

ManufacturerCURT Manufacturing
Part Number56274
UPC612314562749
Package Weight1.46 lbs
Package Dimensions9.0 in x 6.0 in x 3.0 in

Connector Specifications

Connector TypeT-One (T-connector) vehicle-specific
Trailer Output4-flat (4-wire flat connector)
Wiring FunctionsLeft turn/brake, right turn/brake, tail/running, ground
Splice RequiredNo -- plug-in installation
Brake Controller OutputNot included
12V Accessory CircuitNot included

Electrical Ratings

Circuit TypePassive T-connector (no converter module)
Compatibility NoteVerify LED-to-incandescent load matching for your application
SAE ComplianceYes -- SAE-compliant trailer lighting output

What Is Included

Wiring HarnessYes -- vehicle-specific T-connector harness
4-Flat Connector PigtailYes
Mounting Hardware / Cable TiesTypically included (CURT standard kit)
Wiring Diagram / InstructionsYes
Brake ControllerNot included
Hitch Ball or Ball MountNot included

Compatibility and Fitment

Fitment TypeVehicle-specific -- confirm year/make/model
Trailer Connector CompatibilityAll trailers with standard 4-flat plug
OEM Wiring ModifiedNo -- fully reversible installation
Important Information -- Read Before Installing
  • This harness is vehicle-specific. Installing on an incompatible vehicle will result in connectors that do not fit or incorrect signal routing. Confirm your exact year, make, model, and trim before ordering.
  • This is a 4-flat wiring harness only. It does not provide electric brake controller output, 12V battery charge, or backup light signals. Trailers with electric brakes require a 7-way connector system.
  • This harness is a passive T-connector. It does not include a load converter or diode module. If your tow vehicle has LED tail lights and your trailer has incandescent bulbs (or vice versa), check whether a converter is needed to prevent signal interference or lamp-out warnings.
  • Do not exceed the current rating of the vehicle's factory tail light circuit. Adding multiple high-draw trailer lights beyond factory circuit capacity may blow fuses.
  • Keep the 4-flat connector pigtail secured away from exhaust components, moving suspension parts, and areas where it could collect road debris or moisture.
  • Test all trailer lighting circuits before towing on public roads. Trailer running lights, brake lights, and turn signals are required by law in all US states and Canadian provinces.


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