How to Wire a Relay for Lights | Step-by-Step Guide

In this article, we’ll discuss how to wire a relay for lights. You must follow each step clearly in order to correctly connect the relay and lights without wasting your time.

Before we go into detail about how to wire a relay for lights, you should know what the role of the relay in our electrical connections is.

So, let’s start this article by highlighting how relays work in our electrical circuits. Relays are typically used to control the flow of current in one circuit by altering the flow of current in the other circuit. Thus, it acts as a communication link between high- and low-current circuits.

Moreover, every relay comes with a circuit diagram drawn over it, and by knowing a few basics about its pins, one can wire a relay for plenty of applications.

In order to connect the relay in a circuit to perform switching operations between multiple LEDs, we’ve got to carefully connect these pin connections. Only then would a circuit be properly implemented and functional.

Now, let’s find out how we can wire a relay for light!

How to wire a relay for LED lights

If you can understand the circuit diagram involved in wiring the relay for a given application, then it won’t take you long to set everything up. In our case of wiring the relay for LED lights, we’ll implement the below circuit:

In order to wire a relay for LED lights, we’ll need a 4-pin relay, a battery powering the relay, a switch to control the circuit, and LED lights that are to be wired for any application. If you are wiring LEDs installed in any other appliance, even then, the same process will be used.

Now, follow the below-mentioned steps to perfectly wire a relay for LED lights:

  1. First of all, connect the pin labeled 30 positive supply of the battery with a fuse integrated between them. The fuse will protect our whole circuit in case excess current flows towards the relay or LEDs.
  2. Now, ground pin 86 is shown on the left side of a relay in the above circuit diagram.
  3. After grounding pin 86, connect one terminal of the switch to pin 85 of the relay and join its other end to the positive terminal of the battery.
  4. Lastly, connect the positive connection of the LED lights to pin 87 of the relay and ground the negative terminal of the LED lights.

This is how you can wire a relay for LED lights. Whatever application you are working with, the process will be exactly the same. As soon as you turn on the switch, the current supply to the LED lights will light them up.

But what if you’ve bought a 5-pin relay instead of a 4-pin one? Can you use that for LED lights? Yes, you can. In the below section, we’ve discussed how you can wire a 5-pin relay for LED lights!

How to wire a 5-pin relay for LED lights

In the 5-pin relay, there are five connection pins instead of four, represented by 85, 86, 30, 87, and 87A. Just like in the previous case, we’ll need similar components, and similar steps will be followed, but the circuit will be different than the previous one.

In order to wire a 5-pin relay for LED lights, we’ll use the below circuit diagram:

For the rest of the steps, please check out the above section, where we have briefly explained each and every step that is required to wire a relay for LED lights!

Do you need a relay for LED lights?

You have to install a circuit to control the light sufficiently when adding LED lights, off-road light bars, driving or work lights, or other auxiliary lights to a car. Relays are an easy, versatile way to do this. So yes, we need relays for LED lights. It’ll simply make the overall connection process simpler and help you save both money and time.


Can relays go bad?

A relay goes bad when either one or all of its connections fail to work. Two major causes include operating the relay at full load or contact material erosion. However, relays don’t go bad within a few days or weeks. On average, a relay can be good for 100,000 operations when asked to hot-switch a load.

If a relay clicks, is it bad?

Yes, if a relay clicks, there is a possibility that it has gone bad. It is one of the major symptoms of the faulty relay. This mostly has some loose connections in the relay!

Does a relay have polarity?

Although polarity will decide the position of the magnetic field in a DC relay, But note that the magnet works on a lump of iron. typically not a magnet itself. So, polarity is meaningless in general in the case of relays.

Final Thoughts!

This is how you can wire a relay for lights. Follow each step carefully and connect the pins at their right connections to avoid burning out either the relay or the lights. Also note that the connection would be slightly different for other types of lights, like fog lights or light bars.

Leave a Comment