4 Wire Tail Light Wiring Diagram: A Comprehensive Guide

Are you having problems with your tail light wiring? Do you need help figuring out how to properly wire your 4 wire tail lights? Look no further! This article will provide you with a comprehensive guide on how to wire your 4 wire tail lights. We will cover everything from the basics of tail light wiring to common troubleshooting problems, and everything in between.

Understanding Tail Light Wiring

The first step in wiring your 4 wire tail lights is to understand the basic wiring of tail lights. Tail lights are divided into two main parts: brake lights and running lights. Brake lights use a brighter filament to signal that the vehicle is braking, while running lights use a dimmer filament to signal that the vehicle is running. Both are important for safety and should be wired correctly.

On most vehicles, tail lights are powered by the vehicle’s electrical system. The power is sent through a fuse and relay to the tail lights. The tail light wiring has four wires: the ground wire, brake light wire, running light wire, and reverse light wire. Each of these wires serves a specific function and must be wired correctly for the tail lights to work properly.

It is important to note that the wiring of tail lights can vary between different vehicle models and makes. Always consult your vehicle’s owner manual or a professional mechanic before attempting to wire your tail lights.

The Ground Wire

The ground wire is the black wire in the tail light wiring harness. It is responsible for providing a ground connection for the tail lights. Without this connection, the tail lights will not function properly. The ground wire should be connected to a metal part of the vehicle’s frame or body, where it can make a solid connection to ground.

The Brake Light Wire

The brake light wire is the red wire in the tail light wiring harness. It is responsible for providing power to the brake lights when the vehicle is braking. When the brake pedal is pressed, the brake light switch sends a signal to the brake light wire, which activates the brake lights. Make sure the brake light wire is connected to the correct wire on the brake light switch.

The Running Light Wire

The running light wire is the brown wire in the tail light wiring harness. It is responsible for providing power to the running lights when the vehicle is running. This wire should be connected to the vehicle’s running light circuit. On most vehicles, the running light circuit is powered by the same fuse and relay as the tail lights.

The Reverse Light Wire

The reverse light wire is the green wire in the tail light wiring harness. It is responsible for providing power to the reverse lights when the vehicle is in reverse. This wire should be connected to the vehicle’s reverse light circuit. On most vehicles, the reverse light circuit is powered by the same fuse and relay as the tail lights.

Wiring 4 Wire Tail Lights

Wiring 4 wire tail lights can be a challenging task, but with the right tools and instructions, it can be done successfully. The following steps will guide you through the process of wiring your 4 wire tail lights:

Step 1: Disconnect the Battery

Before you start wiring your tail lights, it is important to disconnect the battery to prevent any electrical shocks or accidents. Make sure the battery is disconnected before you start working on the tail lights.

Step 2: Remove the Old Tail Lights

If you are replacing old tail lights, you will need to remove the old tail lights first. Use a screwdriver to remove the screws that hold the tail lights in place. Carefully remove the old tail lights from the vehicle.

Step 3: Install the New Tail Lights

Install the new tail lights in the same location as the old tail lights. Use the screws that came with the new tail lights to secure them in place. Make sure the new tail lights are properly aligned and level.

Step 4: Connect the Wires

Connect the wires to the new tail lights. The ground wire should be connected to a metal part of the vehicle’s frame or body. The brake light wire should be connected to the brake light switch. The running light wire should be connected to the running light circuit, and the reverse light wire should be connected to the reverse light circuit.

Step 5: Test the Tail Lights

After you have connected the wires to the new tail lights, it is important to test the tail lights to make sure they are working properly. Reconnect the battery and turn on the vehicle. Test the brake lights, running lights, and reverse lights to make sure they are working correctly. If everything is working properly, you have successfully wired your 4 wire tail lights.

FAQ

Question Answer
What is the ground wire in tail light wiring? The ground wire is responsible for providing a ground connection for the tail lights. Without this connection, the tail lights will not function properly.
What is the brake light wire in tail light wiring? The brake light wire is responsible for providing power to the brake lights when the vehicle is braking. When the brake pedal is pressed, the brake light switch sends a signal to the brake light wire, which activates the brake lights.
What is the running light wire in tail light wiring? The running light wire is responsible for providing power to the running lights when the vehicle is running. This wire should be connected to the vehicle’s running light circuit.
What is the reverse light wire in tail light wiring? The reverse light wire is responsible for providing power to the reverse lights when the vehicle is in reverse. This wire should be connected to the vehicle’s reverse light circuit.
What should I do if my tail lights are not working? If your tail lights are not working, you should first check the wiring to make sure it is properly connected. You should also check the fuses and relays that power the tail lights. If the wiring and fuses are all in good working order, you may need to replace the tail light bulbs or the tail light assembly.

Conclusion

Wiring 4 wire tail lights can be a challenging task, but with the right tools and instructions, anyone can do it. Remember to always consult your vehicle’s owner manual or a professional mechanic before attempting to wire your tail lights. Always disconnect the battery before working on any electrical system. Following these simple steps will ensure that your tail lights are wired correctly and working properly.