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How to wire Towbar and Trailer Plugs & Sockets

Our trailer wiring diagrams will show you how to wire a trailer plug or socket the right way with a variety of different trailer plugs and socket types for safe, reliable towing.

7 Pin Flat Plug and Socket

The most common 7 Pin connector wiring used when towing light trailers, boat or horse trailers, towbar mounted bike rack with lighting, etc.

7pin flat plug and socket wiring diagram

Note: All diagrams are as viewed from the Cable Side

12 Pin Flat Plug & Socket

This is an extension of the 7 pin flat. The 7 pin flat plug will fit into a 12 pin flat socket and work perfectly.

12 pin flat trailer socket and plug wiring diagram

Note: All diagrams are as viewed from the Cable Side

Small 7 Pin Round (QLD)

Identifying: The plug diameter is similar to the diameter of an Australian 10c coin. There is a larger gap between pins 1 and 6 on the plug, however some trailer companies rotate this connector so that the yellow (pin 1) is at the top. Both the socket and the plug are keyed.

small round trailer socket and plug wiring diagram

Note: All diagrams are as viewed from the Cable Side

Large 7 Pin Round (VIC)

Identifying: The plug diameter is similar to the diameter of an Australian 20c coin. All pins evenly spaced. Both the socket and the plug are keyed.

large round 7 pin trailer socket and plug wiring diagram

Note: All diagrams are as viewed from the Cable Side

Heavy Duty 7 Pin Round

Identifying: The plug diameter is similar to the diameter of an Australian 50c coin. The Earth pin is larger than the other pins. There is no key, other than oversized earth pin, on the socket or plug.

heavy duty 7 pin round trailer socket and plug wiring diagram

Note: All diagrams are as viewed from the Cable Side

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