Plug-and-play trailer wiring harness for select Ford, Lincoln, Mazda, and Mercury SUVs and vans. No cutting or splicing required. SMT-powered converter, 4-way flat output, rubber dust cover included. 12V negative ground systems only.
If your Ford Edge, Ford Escape, Ford Freestar, Lincoln MKX, Mazda Tribute, or Mercury Mariner didn't come with factory trailer wiring, the CURT 56329 is the cleanest, fastest way to add it. Rather than splicing into your vehicle's taillight circuits — which risks damaging delicate electronics — this custom T-connector uses vehicle-specific OEM-compatible plugs that snap directly into the existing taillight wiring harness connectors. No wire cutting, no soldering, no guesswork.
The powered SMT converter at the heart of this harness draws electrical load directly from the battery instead of passing trailer amperage through your vehicle's taillight circuits. This protects sensitive wiring from being overloaded and is essential on modern vehicles with LED taillights or body control modules. The result is a clean, standard 4-way flat trailer connector at the rear of your vehicle that powers your trailer's running lights, brake lights, and left and right turn signals — everything a basic light trailer needs to be road-legal.
OEM-compatible vehicle-side plugs snap directly into your existing taillight harness connectors — zero wire cutting or soldering required
Surface-mount technology converter draws power from the battery — protects vehicle taillight circuits from trailer load and overheating
Standard 4-pin flat connector at the rear powers trailer running lights, brake lights, and left/right turn signals
Rubber dust cover snaps onto the 4-way flat socket when the trailer is disconnected — keeps connector clean and corrosion-free
The CURT 56329 is engineered for select years of the following vehicles: • Ford Edge • Ford Escape • Ford Freestar • Lincoln MKX • Mazda Tribute • Mercury Mariner Important: Not all model years of these vehicles are compatible. The CURT 56329 fits select years only. Always confirm your exact year, make, and model using the CURT Vehicle Lookup tool at curtmfg.com before ordering. Installing on an incompatible model year will result in connectors that do not match. This harness is for 12-volt negative ground electrical systems only — standard on all US-market vehicles listed above.
The black power wire MUST be connected to the vehicle battery with a 10-amp fuse. This is not optional — it is required for the powered converter to function and to protect your vehicle's taillight wiring. • Maximum fuse rating: 10 amps. Do not substitute a higher-rated fuse. • Install the fuse after all other wiring steps are complete. • Use 12-gauge wire or larger for the battery power run. • When routing the power wire through sheet metal, use an existing grommet or add a silicone seal to protect the wire from sharp edges. • Do not exceed product ratings: Signal circuits — 3.0 amps per side; Tail/running circuits — 6.0 amps total. Exceeding these ratings can cause overheating, fire risk, and voids the warranty. Disconnect the negative battery terminal before beginning any wiring steps.
Tools Needed: 10mm socket and ratchet, Phillips screwdriver, drill with 3/32" bit (if no grounding point is available) Key Steps (per official CURT installation sheet): 1. Disconnect negative battery terminal before beginning any wiring 2. Remove driver-side taillight assembly (two Phillips screws) to access the taillight harness connectors 3. T into the driver-side taillight connectors using the harness end with the yellow wire — snap-lock connectors must be fully seated 4. Route passenger-side harness (green wire end) behind the rear scuff panels to the passenger taillight; repeat T-in process 5. Ground the white wire ring terminal to bare vehicle metal using the included screw — clean away any rust, dirt, or paint at the grounding point 6. Mount converter box to a flat interior surface using the included double-sided adhesive tape 7. Route black power wire to the vehicle battery using 12 AWG wire or larger; avoid pinch points and hot/rotating components 8. Install 10-amp fuse after all other wiring steps are complete 9. Reinstall all panels, reconnect negative battery terminal, and attach rubber dust cover to 4-flat connector 10. Test using a test light or by connecting a properly wired trailer — verify all four functions
In the Box: • Custom T-connector wiring harness with OEM-compatible vehicle plugs • Powered SMT converter box • Black power lead wire • 10-amp fuse and fuse holder • White ground wire with ring terminal • Grounding screw • Double-sided adhesive foam tape (converter mounting) • Cable ties (power wire routing) • 4-way flat connector socket with rubber dust cover • Butt connectors (for battery power wire extension) NOT Included — May Need Separately: • 12 AWG wire (if a longer battery power run is needed) • Dielectric grease (recommended on all connection points to prevent corrosion — sold separately)
CURT Customer Service: Phone: 877-287-8634 Website: curtmfg.com Verify vehicle compatibility before ordering using the CURT Vehicle Lookup tool at curtmfg.com — enter your year, make, and model to confirm the 56329 fits your specific vehicle. Installation sheet: Official CURT 56329 installation instructions (56329-INS-RD) are available for download at curtmfg.com and include the powered converter lead instruction sheet (CME-PCL-INS).
The 4-way flat connector is the standard for light-duty trailers, boat trailers, utility trailers, and small campers that require only lighting functions — no electric brakes or auxiliary power. If your trailer requires electric brakes or a 12V battery charge circuit, a 5-way or 7-way connector system will be needed instead.
The T-connector is the most common CURT custom wiring solution. It is always preferable to the splice-in method when a vehicle-specific fit is available, as it preserves the factory wiring integrity and allows the harness to be removed cleanly if needed.