Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
This item does not fit your vehicle
2003 BMW X5
These items fit your vehicle
2003 BMW X5
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Wiring a trailer usually means tracking down the right wires to splice, but this harness skips all that. The Curt T-Connector plugs directly into the vehicle’s tail light connectors to create a 4-pole flat trailer socket. It’s a plug-in design that keeps factory wiring intact, so there’s no cutting or guessing which wire goes where.
The harness includes a powered converter that draws power straight from the battery instead of the tail light circuits. That means it safely isolates the trailer load from the vehicle’s sensitive electronics. A clean ground connection and solid converter power input keep brake, turn, and running lights working as they should with no overload on factory wiring.
Once installed, the 4-flat connector gives you the standard lighting signals—running lights, turn signals, and brake lights—used on most small and mid-size trailers. It’s a simple setup that gets you towing without extra adapters or complexity.
If something stops working, the design makes it easy to test the harness. You can check voltage at the input and output sides of the converter box with a circuit tester to pinpoint any issue. A clean ground connection and corrosion-free trailer plug keep everything running smoothly for reliable lighting every trip.
Customer Satisfaction Score:
77% were satisfied with this product
23% of customers were not satisfied
Ratings & Reviews
Loved it. Simple enough to install. Follow the layout on the print and you’re good. Pleased
The wiring is pretty easy and fast to do by yourself if you are handy. One thing I would like to see for this product is a professional instal video on my sedan. They only have a video up for the wagon which has few key features different.
Plug and play. It was super easy!
Flawless install, everything needed was included, and the instructions are excellent
Make sure you connect it to the correct pole of the battery... You can end up chasing your tail if your dumb like me . Other than that the installation is easy and it works like a charm!
I ordered the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector for my Subaru a year ago and it's still going strong. I'm using it to haul a utility trailer that I use for hauling yard waste, lawn mower and snowblower.
Even though this product said it was for my make and model, the tail light converter did not work. I contacted e-trailer and they worked hard to insure they got me the correct one and also updated their website product specs to reflect the correct information. For this reason I am giving them 5 stars.
Me a llegado super rápido la piesa lo r ecomiendo
Wrong product, late, and poor tracking updates to even let me know it would be late.
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