When you are trying to wire up a light bar, especially an LED one that comes with a large amp, you definitely need to have a relay switch.
For most of the cases, many of us become perplexed while wiring up the relay for LED lights and often make mistakes. In this article here, we will be explaining the step by step process of how to wire a relay for LED lights. So, stay tuned.
What Is Relay?
Well, before wiring a relay, you need to know what exactly it is. Depending on the electronic products, there are a variety of relays you can find. It’s an electric switch to control the current of the circuit.
It can be used to trigger high current from low-current, turn a circuit on or off, alternate the polarity, etc.
In order to add a light, say an LED one; you need to place a circuit that will distribute the power according to the right measure. To do this, the easiest option you have is to use a relay. It will save you money, as well.
Breaking a Relay Down
There are two parts of a relay. The first one is a coil that is inductive. It does the trigger work of the whole system. When you apply a Positive and a Ground to the grounds, you can see the electricity starts to pass through the inductive coil. This way, a magnetic field is generated, and it moves the switch.
Now the other part of a relay is the switch. It has three contacts – common, normally open, and normally closed. By normally, it means it is not yet energized.
By normally open, it means the pin is not connected to the common terminal, and by normally closed, it means the pin is connected. When the pin 87a and 87 are connected to only pin 30, it is known as the common terminal.
Types of Relays
There are basically two types of Relays. Electromechanical (EMR) and Solid State (SSR). The EMR contacts get opened by a magnetic force. For an SSR one, there is no need for a contact, and the switching of it is entirely electronic.
Which one should you use? This question could be answered depending on the electric requirements and life expectancy of the application.
Recently, the SSR has seen a rise in popularity among users, but the most common type of relay is the EMR one. EMR is mostly used for heavy-duty equipment that requires switching capabilities of the EMR.
Both types of relays have their pros and cons in usage. The SSR demands less voltage to turn it on or off, as it doesn’t have to pass energy to any coil or open a contact.
Moreover, as the SSR doesn’t need to conduct any physical movement of any of its parts, it turns on and off faster than the EMR ones.
On the other hand, the EMR one comes with fewer complications when it comes to replacing any parts. If anything goes wrong, you can change the problematic part of it. However, for SSR, you need to change the whole SSR, as it doesn’t involve any of its parts to move.
Do I Need a Relay?
Well, if the light you are using does have a large amp, you should consider using a relay to prevent overheating on the switch or the wire burn-ups. Overall, it will limit the amount of current that gets to the light. For lower amp lights, you may not need a relay switch, but lights like an LED light bar, do call for one.
How to Wire Your LED Light Bar Using a Relay?
Okay, now we will be going through the steps of wiring an LED light with a Relay. Here’s how you do it.
What Are We Working With
A relay has 4 different prongs on it. All the prongs are marked as 4 different numbers – 30, 87, 85, and 86. It may sound confusing to some.
To save you from this confusion, there are some brands that come with being pre-wired and plugged. You don’t need to know anything about these numbering in those cases.
However, you need electricity to activate the LED light bar. So, you need to go through some sort of reworking here.
This happens in some cases, like if you want to make the current flow as you turn the high beams on. Or when you are turning the reveres lights on. That’s when you are adding back up LED light.
Here, we are going to go through the numbers that we mentioned.
The 30 and 87
The number 30 and 87 carry on the task of switching to the LED lights. This switch remains open by a default position. In this way, the battery can’t pass the electricity to the lights.
The 30 acts like the main powerhouse for the LED lightbar. Through this, the battery’s positive end gets connected to a power source (A switched one). It receives power only if the ignition is turned on.
As for the 87, you can see it is going to the positive part of the LED light.
The 85 and 86
Now come the 85 and 86 numbers. These use current and create a magnetic force around it. It eventually closes both the 30 and 87 switches. This way, it widely opens the way for the electricity to run to the lights.
The magnetic force can’t be created if there is no current. That’s why the 30 and 87 switches must be stayed open, and the lights should be turned off.
Specifically speaking, the 85 works as a connector. It connects the main power initiator of the controlling switch.
Besides that, the 86 establishes a connection to the ground. Remember, you can use the 85 and 86 by reverse position, as well. It depends on your decision and the type of harnesses you are using. Some come with a default set up.
That’s it! That’s how easy it is to wire a relay. It’s easier done than said! So next time, if anyone asks you how to wire a relay for LED lights, it’s time for you to wear the expert cape in style!