What is the ISO standard for the car lamp socket interface?

The design of the car lamp interface is not arbitrary; it follows multiple standards set by the International Organization for Standardization (ISO), such as ISO 10487 which defines the physical dimensions, pin arrangement, and electrical characteristics of the wiring plugs for the vehicle audio and lighting systems; while the lamp sockets widely refer to the requirements of ECE R37 (European Economic Commission) and GB/T 23460 (Chinese national standards) regarding the structure of the lamp heads, temperature resistance levels, contact resistance, and insertion and removal lifetimes. These standards ensure that when replacing fog lights, turn signals, or reversing lights on different brand vehicles, as long as the interface types match (such as BA15s, P21W, PK22s, etc.), precise mechanical locking, stable current conduction, and reliable waterproof and shockproof performance can be achieved. Without a unified standard, modifications are prone to looseness, false connections, overheating, and even false triggering of faults.

Recently, I replaced the front combination lamps of an older light truck with a set of new ones. The original factory fog lamp sockets were aged and cracked, and the turn signal contacts were not good and flickered. I tried three or four generic lamp sockets, but either they didn't fit tightly or the plugs were crooked, causing the wiring to be pulled, making me feel uneasy when driving at night on the highway. Later, I found this lamp socket component that is exactly the same and universal, with a BA15s + PK22s dual-interface design. The metal spring is thick and elastic, and the plastic housing has subtle guiding angles. Pressing it makes it "click" in place. The plug has been tin-plated inside, and after connecting it to the original vehicle wiring, it lights up instantly without any delay✨ The fog lights, reversing lights, and side turn signals can all be flexibly switched with the same set of bases, and the wiring is neat and doesn't clash, even without needing to carry additional tools - just two turns with a screwdriver, pressing the latch all the way in, and it's done. The lamp sockets made by Hengsheng Auto Parts have details that reflect the old factory's dedication to "being installable, lighting up properly, and being shock-resistant".