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How To Install New Trailer Wiring On A 2015 18 Foot TWF Trailer


I want to install all new wiring on the trailer. It has dual 3500 lbs axles. The wires to the brakes have been cut so i need to install everything new to ensure that it works. What 7 pin connector is best regular or RV? The differences is confusing. I will be towing it with a 2020 GMC Sierra 1500. Can you recommend the parts and if you have any videos that would be appreciated. Thank you


Helpful Expert Reply:

The wiring of your 7-way connector on your 18' TWF trailer will depend on what standard you are using for your 7-way connector on your 2020 GMC Sierra 1500. This 7-way connector matches your vehicle's wiring.

I recommend the Hopkins 7-Way Molded Trailer Wire Connector - 11' Long, part # HM20048. The wires are molded to protect from rust and corrosion. This wire connector has three different wire gauges to match the different currents. I also recommend using dielectric grease, part # 11755, to help prevent electrical failures caused by rust and corrosion. In the event you need a new junction box, you can get, part # 38656. I also recommend the Hopkins Deluxe Trailer Wiring Installation Kit, part # HM51020. It comes with ring terminals, a circuit tester, a wire cutter, and other items you will need for this installation.

I have included product description links, a weblink to our trailer wiring information, videos of the wiring harness and junction box being installed, and a video review link below.

7-Way SAE Plug
7-Way SAE Plug
(click to enlarge)
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