Nearly every trailer requires a connection
to the towing vehicle’s electrical system through trailer wiring. When it comes
to wiring your trailer, you might be wondering, how exactly should these wires
be connected? By reading this article, you will learn the specific steps for
wiring your trailer.
Trailer Wiring Diagrams
Trailer Wiring Connectors usually come with 4 to 7 pins, offering a range of options for transmitting lighting power and other auxiliary functions. The more functions a trailer has, like trailer brake controllers or backup lights, the more pins it will require. The diagram below simplifies the understanding of what each colored wire represents.
Click on image to enlarge
4-Pin Trailer Wiring Diagram
This is the most basic type of trailer wiring connector. Following standard wiring practices is crucial for safety. Incorrect color connections may lead to malfunctioning or mismatched tail lights, causing confusion while driving. Refer to the diagram for proper wire connections.
Green: Right turn / brakes
Yellow: Left turn / brakes
Brown: Taillights
White: Ground
5-Pin Trailer Wiring Diagram
Compared to the 4-pin trailer wiring, the 5-pin version includes an additional blue wire for the reverse lights. However, not all trailers have reverse lights; it’s advisable to confirm with the seller.
Blue: Reverse lights
Yellow: Left turn / brakes
Green: Right turn / brakes
Brown: Taillights
White: Ground
6-Pin Trailer Wiring Diagram
The 6-pin trailer wiring includes two additional functions over the 4-pin: a wire for the trailer brake controller and another for a 12V auxiliary power supply. This wiring style is commonly found in gooseneck trailers.
Black: +12 volt
Blue: Reverse lights
Yellow: Left turn / brakes
Green: Right turn / brakes
Brown: Taillights
White: Ground
7-Pin Trailer Wiring Diagram
There are two types of 7-pin trailer connectors: one is round and the other is an RV blade plug. Different colors represent different functions, as detailed in the diagram below:
Round 7-Pin Wiring Diagram
Red: Auxiliary power
Black: Reverse lights
Blue: Electric brakes
Yellow: Left turn / brakes
Green: Right turn / brakes
Brown: Taillights
White: Ground
RV Blade 7-Pin Trailer Wiring Diagram - SAE
Grey: Reverse lights
Orange: +12 volt
Blue: Electric brakes
Yellow: Left turn / brakes
Green: Right turn / brakes
Brown: Taillights
White: Ground
If you are looking to purchase a trailer, feel free to contact Three Horses Trailer. We are committed to providing you with top-notch service.
Depending on your region, we will equip your trailer with the appropriate wiring connector. Even if you lose your electrical connection diagram, don’t hesitate to reach out to us. We are here to assist you and resolve any issues you may have.
