7 Pin vs 12 Pin Trailer Connectors

Trailer connectors come in a range of different shapes and sizes, with different pin configurations to suit different trailer applications. It is a topic that has confused many, so in this blog we will endeavor to outline the key differences between 7 and 12 pin trailer connecters and what the typical applications are for both. Connectors come in both flat and round configurations, however the pins themselves remain unchanged, only the way the plug and socket are connected.

7-Pin Trailer Connector

The traditional 7-pin trailer connector is the one most commonly found on passenger cars and will do the job for most basic towing applications. First, we are going to explain what each of the 7 pins actually do, then outline under what circumstances you’re likely going to require this plug. Each of the 7 pins serves as a connection for a different output on the trailer itself.

1. Left hand turn (Yellow cable)
2. Reversing Signal (Black)
3. Earth Return (White)
4. Right Hand Turn (Green)
5. Service Brakes (Blue)
6. Stop Lights (Red)
7. Rear Lights, Clearance, and side marker lights (Brown)

A 7-pin connector will work for most traditional box trailers, smaller boat trailers, and typically any application that does not require any accessories to be run whilst the trailer is in use.

12-Pin Trailer Connector

12-Pin trailer connectors allow users to run accessories via 5 extra pins. All 7-pins mentioned above are included however in addition the plug will also include:

1. Left hand turn (Yellow cable)
2. Reversing Signal (Black)
3. Earth Return (White)
4. Right Hand Turn (Green)
5. Service Brakes (Blue)
6. Stop Lights (Red)
7. Rear Lights, Clearance, and side marker lights (Brown)
8. Battery Charger/Winch (Orange)
9. Auxiliary/Battery Lead (Pink)
10. Earth Return (White)
11. Rear Fog Lamp (Grey)
12. Auxiliaries (Purple)

12-pin connectors are typically required when towing caravans, which may require refrigerators and other accessories to be run whilst on the go. Additionally, heavier applications such as large fishing boats may also require an electronic braking system or stability control system to ensure safety when on the road.

Narva manufacture many trailer plugs and sockets, including both 7 and 12-pin variants in both flat and round forms. We also produce a range of adapters to ensure the correct fit for whichever socket your car comes equipped with. To see the full range of connectors and adapters, visit our online product guide or contact us for more information.