ISO 1724 (7-Pin)
Towing & Hitches · 8 specs
Direct Answer
The ISO 1724 Connector (commonly known as the European Type 12N 7-Pin plug) is the classical European standard for basic trailer lighting. Featuring a circular 7-pin metal or plastic housing with split brass pins, it provides the essential exterior road lighting circuits (left/right turn, isolated left/right tail lights, brake lights, and rear fog lamp).
Source: ISO 1724:2003 (Road vehicles — Connectors for the electrical connection of towing and towed vehicles — 7-pole connector type 12 N) · Last reviewed Aug 28, 2026
Specs
| Standardization | ISO 1724 / DIN 72577 (Type 12N–Normal) |
| Pin 1 (Yellow–Terminal L) | Left Hand Direction Indicator (Turn signal) |
| Pin 2 (Blue–Terminal 54G) | Rear Fog Lamp (or +12V permanent feed on older caravans) |
| Pin 3 (White–Terminal 31) | Common Chassis Ground Return |
| Pin 4 (Green–Terminal R) | Right Hand Direction Indicator |
| Pin 5 (Brown–Terminal 58R) | Right Hand Tail Light, Clearance Lights, and License Plate Lamp |
| Pin 6 (Red–Terminal 54) | Brake / Stop Lights |
| Pin 7 (Black–Terminal 58L) | Left Hand Tail Light and Left Hand Clearance Lights |
The 12N / 12S Dual Plug System
Before the invention of the unified 13-pin ISO 11446 plug, European caravan owners installed two separate 7-pin sockets on their bumper: the black 12N socket (ISO 1724) for legal road lights, and an adjacent grey 12S socket (ISO 3732 / Type 12S–Supplementary) to supply reverse lights and auxiliary power to the caravan interior battery and refrigerator.