Wiring up a 7 Pin Trailer Plug or Socket is a simple and easy process, especially with the following step by step instructions and video demonstration provided. Generally it is the same process with all brands of 7 Pin Trailer Plug or Sockets, however in this demonstration, we will be using the KT Range of Trailer Plugs & Sockets.
We recommend having the following tools handy before moving forward with your installation.
- Wire Stripper (KT Product Code: KTES)
- Cable Cutters/Side Cutters (KT Product Code: KT32034)
- Phillips Head Screw Driver
There are 2 main types of Trailer Cables that are used for wiring your trailer, these are 5 Core and 7 Core. 5 Core does not include the Blue and Black Cables that are traditional used for Blue ( Electric Brakes ) Black ( Aux/ Reverse ) Most trailers particularly box and standard box trailer use 5 Core Trailer Cable. The below chart demonstrates the more technical specifications of each cables. The length required can be easily cut using your side cutters or cable cutting tool. You want to ensure that you have the correct Trailer Cable for your installation and the correct length depending on how long your Trailer is. We recommend the following Types of Trailer Cable:
Steps to Wiring up your Trailer Plug or Socket:
1. Identify what type of 7 Pin Trailer Plug or Socket you are using from the below Wiring Diagrams. Use this as a guide to which wire colour matches with each circuit.
7 PIN SMALL ROUND TRAILER PLUG WIRING DIAGRAM
7 PIN SMALL ROUND TRAILER SOCKET WIRING DIAGRAM
7 PIN FLAT TRAILER PLUG WIRING DIAGRAM
7 PIN FLAT TRAILER SOCKET WIRING DIAGRAM
7 PIN LARGE ROUND TRAILER PLUG WIRING DIAGRAM:
7 PIN LARGE ROUND TRAILER SOCKET WIRING DIAGRAM:
2. Start by stripping the ends of your Trailer Cable by 5mm using a Wire Stripper. (We recommend a Code: KTES – KT Easy Wire Stripper)
3. Twist the ends of the cable to ensure that the cable stranding does not separate.
4. Take your 7 Pin Trailer Plug or Socket and Unscrew the Cap, remove the Cable Gland and Outer Casing.
5. Using a Phillips Head Screw Driver, Loosen but do not remove the 7 screws. If your Trailer Plug or Socket also contains a Saddle Device, remove this using the Phillips Head Screw Driver.
6. Match each coloured wire to the appropriate circuit (as per relating wiring diagram provided above) and place the wire end beneath the correct screw. Tighten screws while holding cable in place.
7. If your Trailer Plug or Socket uses a Saddle Device (a Device that holds wiring in place), Replace saddle device and tighten screws to secure cable, using a Phillips Head Screw Driver.
8. Replace Cable Gland, Replace Trailer Plug or Sockets outer casing and tighten screw cap. Ensure any screws are tightened.
Your 7 Pin Trailer Plug is now wired up and ready to be used.
See below for complete Video Demonstration of ‘How to Wire Up a 7 Pin Trailer Plug or Socket. In this demonstration, we use a KT Clear Trailer Plug, however the wiring process is exactly the same for any other Trailer Plug.
You May Also be Interested in KT’s LED Trailer Accessory Range:
KT provides a variety of LED Trailer Accessory Products which assist in the detection of faulty trailer wiring systems. The Built-In LED Circuit Tester, tests the circuits for any wiring faults which can be caused by general ‘wear and tear’ or pin corrosion. Faulty Trailer Wiring is a hazard for other road users, causing Trailer Light illumination Failure. This can simply be avoided by completing a quick test on your Trailer Wiring Circuits before setting off on your journey.
Visit www.ktcables.com.au for more information