Trailer & Bike Rack – Type of Electrical Connectors

Trailer and Bike Rack connectors can come in a variety of shapes and sizes depending on where you live in the world?

There is some commonality, as most vehicles have similar lighting requirements:

Table of rear vehicle lights (usually fitted):

Light Type Lighting Circuit
Warning Lights (rear): Tail (or side) lights.
Brake lights.
Turn indicator LH.
Turn indicator RH.
Fog lights.
Ancillary Lights (rear): License (or number) plate lights.

Trailer Connector Differences:

The differences between connectors, typically come down to the following:

  • The number of pins used?
  • The shape of the socket?
  • The pin orientation?
  • Where you live in the world (the standard used)?
  • Male or Female pins, spade or bullet connectors?

The easiest way to show the differences, is to use the table below. You can see many of the physical connections are the same or similar.

Table of electrical connections to a vehicle trailer or bike rack:

Vehicle Warning Lights, Ancillary Lights & 12v Supplies. Australia (+ it’s own variations)
America Europe
Lighting & Power Caravan Socket
DIN * DIN * ISO 11446 12N 12S
ISO 1724 ISO 3732
7 pin 13 pin 7 pin 7 pin
Turn (Indicator) LH. L54 L 1 1
Fog. 2 2
Ground or Common. 31 31 3 3 3
Turn (Indicator) RH. R54 R 4 4
Tail (side), Number Plate RH. 58 58R 5 5
Stop or Brake. 54 54 6 6
Tail (Side), Number Plate LH. 58 58L 7 7
Reversing. 8 1
Power (Continous) 12v. 30 9 4
Power (Ignition Switch) 12v. 15 15 10 6
Ground or Common (pin 10). 31 11
Spare. 12
Ground or Common (pin 9). 31 13
Battery Charging. 2
Spare. 5
Spare or Ground (pin 6). 7

* DIN – This is a standard for electrical terminal numbers on vehicles.

L54 and R54 – In America it is common for the brake lights to be combined with the turn indicators.

A Brief Summary of the type of Trailer Connectors (by region):

American Trailer Connectors:

  • Round socket with either flat blade or round pin.
  • Flat socket with a round pin.
  • Square (rectangular) socket).
  • Generally using 4 to 7 ways (pins).

Australian Trailer Connectors:

  • A mixture of American, European and Australian, dependant of the origin of manufacture.

European Trailer Connectors:

They all have a round pin and round socket configuration:

  • 5 pin, ( Older trailers) similar to the current 7 pin socket.
  • 7 pin.
  • 13 pin (latest).

Socket Types:

Below is an illustration of some of the different socket types.

Please note how the pin number orientation changes dependant on which way you look at the connector…

Trailer Socket 12N 7 Pin (ISO 1724)
Trailer Socket 12N 7 Pin (ISO 1724)
Trailer Socket 12N 13 Pin (ISO 11446)
Trailer Socket 12N 13 Pin (ISO 11446)

See Wikipedia for more information on the different types of trailer connector.

This is also sub-divided into the following different regions:

The Links Below Take you to More Detailed Descriptions on: