How does a 7-pin trailer connector work?
Complete technical explanation
Technical operation of the 7-pin trailer plug
The 7-pin connector provides the electrical connection between the towing vehicle and the trailer. Each pin has a fixed function according to the ISO 1724 standard . This ensures that the trailer's lighting and safety systems function correctly and reliably.
Pin assignment 7-pin plug
| Pin | Function | Application |
|---|---|---|
| 1 | Left turn signal | Road safety |
| 2 | Rear fog light | Mandatory within the EU |
| 3 | Mass | Current return |
| 4 | Right turn signal | Road safety |
| 5 | Rear light right | Position light |
| 6 | Brake light | Safety |
| 7 | Rear light left | Position light |
Why quality is crucial
Cheap connectors can lead to various technical problems, such as:
• Bad ground → flickering or disturbing lights
• Corrosion → failure of electrical connections
• Cable break → liability risk
• Warranty claims
For OEMs and distributors , consistent quality is essential to minimize returns and service costs.
Proshen's quality approach
At Proshen we check, among other things:
• Quality of the brass contact points
• Resilience and durability of the contact pins
• IP protection degree (water and dust protection)
• Cable strain relief
• Salt spray test (corrosion test)
In addition, we actively consider cost optimization , without making concessions on safety or reliability.
