ISO 11446:2004 specifies a 13-pole electrical connector between towing and towed vehicles with 12 volt electrical system.

ISO 11446
Type Trailer Connector
Superseded ISO 1724 (12N)
ISO 3732 (12S)
General specifications
Pins 13
Pinout
Trailercontact13pin.svg
Pin 1 Left indicator
Pin 2 Rear fog lamp
Pin 3 Earth
Pin 4 Right indicator
Pin 5 Right tail lamp
Pin 6 Brake lamp
Pin 7 Left tail lamp
Pin 8 Reverse lamp
Pin 9 Permanent power
Pin 10 Switched supply (for fridge)
Pin 11 Earth for pin 10
Pin 12 Trailer Presence Detection
Pin 13 Earth for pin 9

ReferencesEdit