4 Prong Wiring Diagram Trailer

Hello and welcome to our comprehensive guide on 4 prong wiring diagram trailer. In this article, we will explore the intricacies of wiring a trailer with a 4 prong connector. Whether you are a seasoned DIY enthusiast or a beginner, this guide will provide you with all the information you need to successfully wire your trailer. So let’s dive in!

Subheading 1: Understanding the Basics

Before we delve into the details of the wiring diagram, let’s first understand the basics. A 4 prong wiring diagram is used for trailers that have a 4-prong connector, also known as a 4-way flat connector. This type of connector is commonly found on small utility trailers, boat trailers, and campers.

The 4 prong connector consists of four wires, each serving a specific purpose. The wires are color-coded for easy identification:

Wire Color Purpose
White Ground
Brown Tail Lights
Yellow Left Turn/Brake Lights
Green Right Turn/Brake Lights

Understanding the purpose of each wire is crucial for a successful wiring installation. Now, let’s move on to the wiring diagram itself.

Subheading 2: Wiring Diagram

Here is a detailed wiring diagram for a 4 prong trailer connector:

_______________|||4 Prong||Connector||_______________|||||White||Ground|-----||||BrownYellow||||Tail LightsLeft Turn/Brake Lights||||-----||||Green|||||Right Turn/Brake Lights

As depicted in the diagram, the white wire should be connected to the ground, the brown wire to the tail lights, the yellow wire to the left turn/brake lights, and the green wire to the right turn/brake lights. By following this diagram and connecting the wires accordingly, you can ensure proper functionality of your trailer’s lights.

Subheading 3: Advantages and Disadvantages

Like any wiring configuration, using a 4 prong wiring diagram for your trailer has its own set of advantages and disadvantages. Let’s take a closer look at them:


  • Simple and widely used: The 4 prong wiring diagram is a standard configuration, making it easy to find compatible connectors and components.
  • Clear separation of functions: Each wire serves a specific purpose, allowing for easy troubleshooting in case of any issues.


  • Limited functionality: The 4 prong wiring diagram is suitable for basic trailers with standard lighting systems. If you have additional features like electric brakes or a charging system, you may need a different wiring setup.
  • Not compatible with all vehicles: Some vehicles may require a different wiring configuration, such as a 7 prong connector, which provides more functionality.

It’s important to consider these advantages and disadvantages before choosing a wiring diagram for your trailer to ensure compatibility and functionality.

Subheading 4: Alternative Wiring Diagram

If the 4 prong wiring diagram doesn’t suit your needs, an alternative option is to use a 7 prong wiring diagram. The 7 prong wiring diagram provides additional functionality, such as electric brakes and a charging system. This wiring setup is commonly used for larger trailers and RVs.

The 7 prong connector consists of seven wires, each serving a specific purpose:

Wire Color Purpose
White Ground
Black 12V Battery Power
Blue Electric Brakes
Red Left Turn/Brake Lights
Green Right Turn/Brake Lights
Brown Tail Lights
Yellow Backup Lights/Auxiliary

By using a 7 prong wiring diagram, you can enjoy the added functionality and flexibility for your trailer.


Q: Can I use a 4 prong wiring diagram for a larger trailer?

A: It’s not recommended. A larger trailer with additional features may require a 7 prong wiring diagram for proper functionality.

Q: Are there adapters available to convert a 4 prong connector to a 7 prong connector?

A: Yes, there are adapters available in the market that allow you to convert a 4 prong connector to a 7 prong connector. However, it’s important to ensure compatibility and functionality before using an adapter.

Q: Can I install a 4 prong wiring system myself?

A: Yes, if you have basic knowledge of electrical systems and wiring, you can install a 4 prong wiring system yourself. However, if you are unsure, it’s always recommended to seek professional assistance.


In conclusion, understanding the 4 prong wiring diagram for trailers is essential for safe and functional towing. By following the wiring diagram and considering the advantages and disadvantages, you can make an informed decision on the best wiring configuration for your trailer. Whether you choose the 4 prong or 7 prong wiring diagram, always prioritize safety and consult professionals when needed. Happy towing!