Trailer harness wiring diagram is an essential guide for anyone who wants to tow a trailer. It can be a daunting task to figure out how to wire your trailer harness. There are various types of trailer harnesses and wiring diagrams, and it can be confusing to know which one to choose. In this article, we will provide you with a complete guide on everything you need to know about trailer harness wiring diagrams.
What is a Trailer Harness?
A trailer harness is a device that connects the vehicle’s electrical system to the trailer’s lighting system. The harness provides power to the trailer’s lights, brakes, and turn signals. It allows the vehicle to control the trailer’s lights, enabling drivers to operate their trailers safely and legally.
There are different types of trailer harnesses that you can choose from, including four-pin, five-pin, six-pin, and seven-pin connectors. The type of trailer harness that you need will depend on the type of trailer you have and the number of lights, brakes, and turn signals it has.
Four-Pin Trailer Harness Wiring Diagram
The four-pin trailer wiring diagram is the simplest wiring diagram available. It is a standard wiring diagram used for most small trailers. The four-pin wiring diagram consists of four wires:
| Wire Color | Function |
|---|---|
| Brown | Tail Lights |
| Yellow | Left Turn Signal |
| Green | Right Turn Signal |
| White | Ground |
The brown wire powers the taillights, while the yellow and green wires provide power to the left and right turn signals. The white wire is the ground wire.
When wiring a four-pin trailer harness, it is recommended to use a converter if your vehicle is not equipped with a factory-installed trailer harness. The converter will convert the signals from the vehicle’s electrical system into signals that the trailer can understand. This makes it easier to wire the harness and ensures that the trailer’s lights function correctly.
Five-Pin Trailer Harness Wiring Diagram
The five-pin trailer wiring diagram is similar to the four-pin wiring diagram, but it includes an additional wire for the electric brakes. The five-pin wiring diagram consists of five wires:
| Wire Color | Function |
|---|---|
| Brown | Tail Lights |
| Yellow | Left Turn Signal |
| Green | Right Turn Signal |
| Blue | Electric Brakes |
| White | Ground |
The blue wire provides power to the electric brakes. If your trailer does not have electric brakes, you can use a four-pin harness instead.
Six-Pin Trailer Harness Wiring Diagram
The six-pin trailer wiring diagram includes an additional wire for trailer battery charging. The six-pin wiring diagram consists of six wires:
| Wire Color | Function |
|---|---|
| Brown | Tail Lights |
| Yellow | Left Turn Signal |
| Green | Right Turn Signal |
| Blue | Electric Brakes |
| Red | Trailer Battery Charging |
| White | Ground |
The red wire provides power from the vehicle’s electrical system to the trailer’s battery. This allows the trailer’s battery to charge while the vehicle is running. If your trailer does not have a battery, you can use a five-pin or four-pin harness instead.
Seven-Pin Trailer Harness Wiring Diagram
The seven-pin trailer wiring diagram is the most common wiring diagram used for trailers with electric brakes and other additional features. The seven-pin wiring diagram consists of seven wires:
| Wire Color | Function |
|---|---|
| Brown | Tail Lights |
| Yellow | Left Turn Signal |
| Green | Right Turn Signal |
| Blue | Electric Brakes |
| Red | Trailer Battery Charging |
| Black | Battery Power (Hot) |
| White | Ground |
The black wire provides power to the trailer’s battery through a fuse or circuit breaker. This wire is hot when the vehicle’s ignition switch is on. The seven-pin wiring diagram is the most complete wiring diagram available and can be used for any type of trailer.
FAQs
Q. How do I wire a trailer harness?
A. To wire a trailer harness, you need to connect the wires from the harness to the corresponding wires on the trailer. The process will depend on the type of trailer harness you have and the type of trailer you are towing. Always follow the manufacturer’s instructions and consult a professional if you are uncertain.
Q. How do I test my trailer harness?
A. To test your trailer harness, you will need a test light. First, connect the ground wire of the test light to a good ground on the vehicle. Then, have someone operate the vehicle’s turn signals, brake lights, and headlights while you check each wire of the trailer harness with the test light. The test light should illuminate when the corresponding function is activated.
Q. Can I use a four-pin harness on a trailer with electric brakes?
A. No, a four-pin harness does not provide enough wires to power electric brakes. You will need at least a five-pin harness to power electric brakes.
Q. Can I wire a trailer harness myself?
A. Yes, you can wire a trailer harness yourself if you have the necessary tools and knowledge. However, if you are unsure or inexperienced, it is recommended to have a professional do the wiring for you.
Q. Can I use a seven-pin harness on a trailer with only two lights?
A. Yes, you can use a seven-pin harness on a trailer with only two lights. You would simply not connect the additional wires that are not needed for your particular trailer.
Conclusion
Trailer harness wiring diagrams are an essential guide for anyone who wants to tow a trailer safely and legally. It is important to choose the right type of trailer harness and wiring diagram for your particular trailer and vehicle. Always follow the manufacturer’s instructions and consult a professional if you are unsure. By following the tips and information provided in this article, you can feel confident in wiring your trailer harness and towing your trailer safely.
