GB/T 5053.1-2006

This standard specifies the dimensional, contact arrangement, and performance requirements for 7-pole electrical connectors used to link the electrical systems of towing vehicles (e.g., tractors or trucks) and towed vehicles (e.g., trailers or semi-trailers) operating on a 24V nominal supply voltage. It is applied in the automotive industry, specifically for heavy-duty commercial vehicles and trailers, ensuring standardized electrical connections for lighting, signaling, and auxiliary functions during towing operations. The standard is critical for compatibility and safety in road transport, particularly in regions like China where 24V systems are common for heavy vehicles.