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When you’re upgrading from a 4-way to run trailer brakes or charge a trailer battery, this kit makes it easy. The Curt Universal Installation Kit for Trailer Brake Controller includes the heavy-duty 10-gauge wire and a 40-amp circuit breaker needed to power the 12-volt pin on the 7-way RV connector. It provides the proper feed to your brake controller and sends charging current back to the trailer battery while towing.
Adding a brake controller doesn’t have to mean building a harness from scratch. This kit comes pre-wired with leads marked for power, ground, brake output, and reverse light so you can hook each one directly where it belongs. The plug-and-lead setup saves time and helps prevent mixing up circuits when adding a 7-way for towing electric-brake trailers.
The 7-way socket has separate pins for brake output and constant power, so the controller signal is clean and consistent. You can confirm both using a circuit tester at the 1 o’clock (12V) and 5 o’clock (brake output) positions—12 V stays hot all the time, and the brake pin powers only when the controller’s manual override is pressed. That clear separation helps ensure steady braking response and reliable battery charge while on the road.
For trailers that use backup lights or need an auxiliary circuit, the included red wire gives you that option. If your setup doesn’t use it, just cap it off—no need to modify anything else. Having every circuit ready in one harness means you can configure your wiring exactly how your trailer requires without extra parts or adapters.
The Curt Universal Installation Kit for Trailer Brake Controller # C57186 does not include a mounting bracket for the 7-way connector. If a bracket is needed, it must be purchased separately.
Customer Satisfaction Score:
96% were satisfied with this product
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Ratings & Reviews
Jerry
10/22/2018
Still working great
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7/26/2020
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