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Is Junction Box Recommended When Installing New Trailer Wiring 7-Way


Needing to completely rewire 18 foot auto transport dual axle 7 blade with brake on one axle... Is it best to use a box or just 7 blade connector and straight wiring by the foot....and what do I need for both?....just about to lay all new flooring...rewire before floor goes down... Thanks


Expert Reply:

Using a junction box makes installing new 7-way wiring much easier.

Often times, people will run the wires from a 7-way such as yours to a junction box like part # 38656. From there, they will run the standard wire colors to the trailer lights, brakes and battery. I have attached a photo that shows how this setup works in the junction box. Most molded 7-way pigtails will come wired with the RV style color code. If you ever need to replace your 7-way connector in the future, you could simply open the junction box, remove the connector and wire loom and install a new, molded 7-way trailer connector.

I have attached a video showing the installation of the junction box. In this video, our installer uses a 7-way molded connector with the RV style color code like your 7-way connector. He also uses the traditional wire colors going out of the junction box to the trailer lights and brakes. He uses the appropriate lengths of 16 gauge Bonded 4 Wire, # 16-4B-1, for the trailer lights and 10 gauge Jacketed 2 Wire, # 10-2-1, for the trailer brakes and ground.

Additional hardware that you may need is 3/16 Inch Ring Terminals, # 44-5310A, 1/4 Inch Ring Terminals, # DW05702-1, 12-10 Gauge Butt Connectors, # 05732-2, 16-14 Gauge Butt Connectors, # 05731-5, and electrical tape.

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expert reply by:
Jameson C

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