How to Wire a Relay for Off-Road LED Lights: Beginner’s Guide

Follow our guide on how to wire a relay for off-road LED lights. Insightful information with detailed instructions.

Understanding First Steps

Off-road adventures often demand robust lighting solutions to navigate through challenging terrains safely. Installing LED lights is popular for enthusiasts seeking improved visibility during nighttime adventures.

One crucial step of the installation process is correctly wiring a relay to ensure optimal performance and longevity of the LED lights.

In this guide, we will simplify the understanding of relay switches, outlining their significance and delivering step-by-step instructions for the DIY wiring process. We will highlight their importance and equip you with the knowledge to confidently wire a relay for your high amp draw light bar.

What is a Relay Switch, and Why is it Necessary?

A relay is like a regulating switch in your car’s electrical system. Its job is to let a small flow of electricity control a significant flow, and it’s super handy when dealing with a high-powered LED light bar. Without a relay, your regular switch might get too hot, wires could get damaged, and your light might not shine as brightly.

Installing a relay is an essential piece of gear for your overlanding expeditions. We also have plenty of other overlanding gear suggestions for your next adventure.

How to Wire Your LED Light Bar Using a Relay

Materials needed:

  • Off-road LED lights
  • Relay (with appropriate amperage rating)
  • Wiring harness with a switch
  • Inline fuse
  • Ring terminals
  • Wire strippers
  • Crimping tool
  • Heat shrink tubing
  • Screwdrivers
  • Zip ties

Step 1: Gather your materials and disconnect the battery

Ensure you have all the materials listed above before starting the installation process. For safety reasons, disconnect the vehicle’s battery before beginning wiring work.

Step 2: Mount the LED lights and the relay

Install the off-road LED lights in the desired locations, following the manufacturer’s instructions. Find a suitable place to mount the relay, preferably near the battery, for easy access to power.

Step 3: Connect the wiring harness and the relay

Now it’s time to connect the wiring harness to the LED lights, ensuring a secure and weatherproof connection.

The relay needs to be connected to the vehicle’s battery using appropriate-sized ring terminals. Also, connect the ground wire to a suitable ground point on the vehicle.

Insert the inline fuse into the wiring harness and connect it to the battery-positive terminal.

When connecting the wires, make sure to attach the black wire and the red wire to the correct locations. The black wire represents the negative side and it should be connected to a ground point in the vehicle, while the red wires should be connected to your LED lights. Depending on the different kits, the colors might be slightly different, but black and red wires and the most common colors.

This step will ensure a seamless electrical flow, allowing your LED lights to operate efficiently. Remember, attention to these details provides a hassle-free setup and improves the overall reliability of your LED lighting system.

If you want to use the power from your vehicle’s existing features like brakes, reverse lights, or turn signals for your LED light bar, you’ll need to make some adjustments to get it working. For clarity, we’ll refer to each of these features as a “switch.” It highlights that the on/off functions already present in your vehicle can be utilized like a traditional switch.

Simple Guide for Coded Numbers

Relay Wiring

The relay has four prongs labeled 30, 87, 85, and 86, which may sound like mysterious coded numbers.

Simple guide for the coded numbers:

1. Prongs 87 and 30 together form the switch mechanism for your LED lights. By default, this switch is in the open position, preventing flow from the battery to your lights.

2. Prong 30 is the power source for your LED light bar, linking to the positive (+) side of your battery.

3. Prong 87 is connected to the positive side of your LED lights.

4. Prongs 85 and 86 utilize electrical current to generate a magnetic force, closing the switch between 30 and 87 and enabling the electricity to reach your lights. Without this current, no magnetic force is created, keeping the 30 to 87 switch open, and your lights off.

5. Prong 85 connects to the power source that controls the switch, such as tapping into your high beam switch wire or backup light wire.

6. Prong 86 is connected to the ground.

Keep in Mind

Many companies provide wiring kits alongside their products, and if you need to be better equipped with wiring accessories, opting for the wiring kit is a wise choice. Some companies even bundle the kit with the product itself.

Relays come at a minimal cost and should always be considered. When in doubt about the power requirements of an accessory, it’s always a good practice to incorporate a relay.

Step 4: Test the system

Reconnect the vehicle’s battery and test the LED lights to ensure they function correctly.

Use zip ties to secure the wiring neatly and prevent any interference with moving parts.

What if you prefer more control over when your LED light activates with your high beams or backup lights?

In these scenarios, a good solution involves incorporating an additional switch on your dashboard that you can manually toggle on and off. When this switch is off, activating your high beams won’t turn on your LED light, and vice versa.

To achieve this setup, you’ll need to integrate the dash switch into the trigger current – the line spliced off your high beam or backup light wire.

With a wiring harness, the process is straightforward. Cut the wire extending from the switch to the 30 prongs on the relay and connect it to your high beam lead or backup light wire. This configuration ensures that when your high beams are engaged, the current first flows to the dash switch.

If the switch is off, the electricity won’t reach the 85/86 circuit, preventing the creation of the magnetic force needed to close the 30/87 circuit and, consequently, keeping your LED lights off.

Professional assistance

If you ever feel overwhelmed or uncertain during the installation process, feel free to seek assistance from professionals or experienced individuals.
Remember, successful installation not only ensures proper functionality but also contributes to a safer driving experience.

Final Thoughts

Wiring a relay for off-road LED lights might initially seem overwhelming, but with suitable materials and a practical approach, it becomes an achievable DIY project. Following these steps ensures a safe and reliable installation, allowing you to enjoy your off-road adventures with better visibility and higher confidence. Always refer to the instructions provided by the LED light and relay manufacturers for the best results. Happy off-roading!



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