Electrical system of a passenger car trailer
The trailer’s electrical system is designed to provide the lights, turn signals, brake lights, and other electronic functions of the trailer. It connects to the vehicle’s electrical system to provide power and control.
Electrical connector
The electrical connector serves as the connection point between the vehicle and the trailer. Typically 4, 5, 6 or 7 pin connectors are used, with each pin corresponding to a specific function.
Wire color
The standard wire colors for a trailer’s electrical system are as follows:
*Ground: white
*Left turn signal: yellow
*Right turn signal: green
* Brake lights: red
* Dimensions (number lights): brown
* Reverse (optional): blue
* Trailer brake (optional): black
Connection diagram
The wiring diagram for the trailer’s electrical system depends on the type of connector. Here is the general diagram for a 4-pin connector:
Contact | Wire color | Function
—|—|—
1 | White | Grounding
2 | Yellow | Left turn signal
3 | Green | Right turn signal
4 | Red | Brake lights
Advanced Features
Trailers with additional features such as reverse or trailer brakes require additional pins on the connector.
Installation
Installing a trailer’s electrical system typically involves the following steps:
1. Connect the electrical connector to the trailer.
2. Route the wires from the connector through the trailer to the lights.
3. Connect the wires to the lighting devices, following the connection diagram.
4. Connect the connector to the vehicle’s electrical system.
5. Check the operation of all functions, including lights, turn signals and brake lights.
Maintenance
To ensure optimal performance of your trailer’s electrical system, regular maintenance is recommended, including:
* Check the connector for corrosion or damage.
* Check wiring for wear or damage.
* Clean all electrical contacts.
* Replacement of burnt out light bulbs.