Is Junction Box Recommended When Installing New Trailer Wiring 7-Way
Question:
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
asked by: Gavin M
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.

Products Referenced in This Question
16-14 Gauge Butt Connector - 5 Pack
- Wiring
- Wire Connectors
- Butt Connectors
- 16-14 Gauge
- Deka
more information >
Deka Jacketed 2 Wire, 10 Gauge, Brake Wire - per Foot
- Wiring
- Wire
- Jacketed Wire
- 2 Wire
- 10 Gauge
- Deka
more information >
16 Gauge, 4 Conductor Bonded Parallel Wire - Per Foot
- Wiring
- Wire
- Bonded Wire
- 4 Wire
- 16 Gauge
- Deka
more information >
Ring Terminal - 12-10 Gauge Wire - 3/16" Ring ID
- Wiring
- Wire Connectors
- Ring Terminals
- 3/16 Inch Diameter
- 12-10 Gauge
- Flint Hill Goods
more information >
Ring Terminal -16-14 Gauge - 1/4" Ring ID - Qty. 1
- Wiring
- Wire Connectors
- Ring Terminals
- 1/4 Inch Diameter
- 16-14 Gauge
- Deka
more information >
Product Page this Question was Asked From
16 Gauge, 4 Conductor Bonded Parallel Wire - Per Foot
- Wiring
- Wire
- Bonded Wire
- 4 Wire
- 16 Gauge
- Deka
more information >
Featured Help Information
Miscellaneous Media
Continue Researching
- Q&A: Availability 7-Way Round to 4-Way Flat Adapter
- Shop: Grille Guard
- Shop: Westin HDX Grille Guard with Punch Plate - Black Powder Coated Steel
- Shop: Trailer Wiring
- Video: Let’s Check Out the Westin HDX Grille Guard with Punch Plate
- Shop: Trailer Hitch
- Shop: Adapter 7-Pole Round Pins To 4-Pole Flat
- Shop: 7- and 4-Pole Trailer Connector Socket w/ Mounting Bracket - Vehicle End
- Shop: Curt Universal Wiring Harness for Vehicle-End Trailer Connectors
- Shop: Curt Trailer Connector for Ford and GM Trucks - Backup Alarm - 7-Way Blade and 4-Way Flat
- Shop: Hopkins Endurance Multi-Tow 7-Way RV and 4-Way Flat Trailer Connector - Vehicle End
- Video: Finding the Right Trailer Wiring Harness
- Video: Curt Universal Wiring Harness for Vehicle-End Trailer Connectors Review
- Shop: Universal Light Clamps for Westin HDX Grille Guard - Black Powder Coated Steel - Qty 2
- Q&A: How to Know if the Curt Trailer Connector for Ford and GM Trucks - Backup Alarm Will Fit a Vehicle
- Search Results: trailer harness
- Search Results: 7 pin adapter
- Search Results: trailer lights
- Search Results: hm40950
- Q&A: What is the Punch Plate of the Westin HDX Grille Guards
- Q&A: Adapting 7-Way Round Pin on Mack Semi-Tractor to 7-Way Blade Style RV Connector
- Search Results: grille guard
- Search Results: 5/8 inch hitch pin
- Search Results: 5/8 inch diameter hitch pins and clips
- Video: Install: 7- and 4-Pole Trailer Connector Socket w/ Mounting Bracket on a 2018 Chevrolet Traverse
- Video: Hopkins 7- and 4-Pole Trailer Connector Socket Installation - 2020 Chevrolet Silverado 1500
- Video: Installing the Curt Trailer Connector for Ford and GM Trucks on your 2015 Jeep Grand Cherokee
- Video: Ultimate Overview of the Thinline LED Trailer Tail Light
- Q&A: Class V Trailer Hitch Fit Recommendation for 2002 Ford F-250 with Full Sized Spare
- Q&A: Are there Mounting Tabs to Add Fog Lights on Westin HDX Grille Guard for 2008 Ford F-250