Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
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2012 Ford Expedition
These items fit your vehicle
2012 Ford Expedition
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Wiring for trailer lights doesn’t have to mean cutting into factory wires. The Curt T-Connector plugs directly into the vehicle’s tail light harness and gives you a standard 4-flat trailer connector. No splicing or guessing which wire does what—just connect the plugs and it’s ready to go.
This harness includes a powered converter that draws power straight from the vehicle battery instead of the tail light circuits. That setup keeps the vehicle’s sensitive wiring safe from overloads or shorts. The included power wire runs up to the battery to handle the trailer light load without risking damage to the vehicle’s electrical system.
The best way to route the converter’s power lead is along an existing wiring path under the vehicle. Zip-tie it every couple of feet and keep it clear of hot or moving parts like the exhaust or suspension. On gravel roads, sliding a section of wire loom over it helps shield against rocks and debris for long-term protection.
Once installed, the 4-flat connector provides running lights, turn signals, and brake lights for your trailer. Make sure both the vehicle and trailer grounds are attached to clean bare metal for a solid connection—good grounding keeps all lights working properly without flicker or failure.
If you ever lose a signal at the trailer connector while inputs still test correctly at the converter box, it’s likely just a failed converter module. The modular design makes replacement straightforward—swap in a new box and the rest of the harness stays in place, keeping downtime to a minimum.
Customer Satisfaction Score:
95% were satisfied with this product
5% of customers were not satisfied
Ratings & Reviews
James L.
1/28/2019
I am pleased with the hitch and wiring harness. I recently used them to tow a U-haul trailer loaded with a motorcycle from Colorado to Arkansas. Both products worked flawlessly.
John
4/21/2019
I like the fact that the trailer connection is stored inside the car by the spare tire. I see other connectors dangling loose outside of the car a lot.
Mike S.
12/24/2017
Great, no trouble on the install or since while using it.
Craig H.
9/8/2017
excellent
Lonnie
8/5/2016
The hitch is working great, the wiring is also working out very well.
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Chris
8/17/2026
This product has held up well and has been very useful!