A semi-trailer typically has two types of electrical connectors for lighting and signaling purposes: the 7-pin connector and the 15-pin connector.
The 7-pin connector, also known as the SAE J560 connector, is the most common type used in North America. It consists of seven pins arranged in a circular pattern. Each pin has its specific function:
Left turn/brake lights: This pin connects to the left turn signal and brake lights of the trailer.
Auxiliary or backup lights: This pin is used for auxiliary lamps or backup lights.
Ground wire: It provides a ground connection to the trailer.
Right turn/brake lights: This pin connects to the right turn signal and brake lights of the trailer.
Electric brakes: Used for electric brakes on the trailer.
Tail/marker lights: This pin supplies power to the tail lights and marker lights of the trailer.
12V power supply or battery charging: This pin provides a 12-volt power supply or charges the trailer's battery.
The 15-pin connector, also known as the ISO 12098 connector, is commonly used in Europe and other regions. It provides additional functionality compared to the 7-pin connector. The extra pins allow for the connection of various trailer systems, such as ABS (anti-lock braking system) and EBS (electronic braking system). The exact pin configuration and functions may vary depending on specific trailer requirements and regional standards.
These electrical connectors enable the transmission of signals and power between the towing vehicle and the semi-trailer, allowing for proper operation of the trailer's lighting, braking, and other electrical systems during towing.
