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How to Wire LED Light Bar Without Relay

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If you are a regular driver, it is necessary to have sufficient light when on the road at night. Having an LED Light bulb wired is one essential step towards achieving confident driving. Sometimes you might want to avoid using a relay when wiring the LED light. That is why we prepared this step-by-step guide to help you learn how to wire LED light bar without a relay.

How to Wire LED Light Bar Without Relay

This guide will show you how you can wire your LED light bar with a switch instead of the relay. To do this, you first need to understand the process involved in connecting the LED lights to the switch.

How to Wire LED Light To a Switch

Before wiring the LED lights bar to the switch and the lighting system of a vehicle, you need to do the following three things: 

Cars with headlights on

Select the LED

Two factors that will determine the LED that you settle on: color temperatures and its operating life. Light Emitting Diodes (LED) with higher color temperatures tend to be effective. The average lifespan of LED light bars varies between 20,000 to 50,000 hours.

Select An Appropriate Power Supply

The power supply that you choose should have wattage and voltage suitable for the LED that you pick. You need to select an LED that has the same value for voltage and amperage.

Pick The Resistor

The essential part of this step is calculating the voltage and amperage before determining the resistor that you want to use. High current values are disastrous and may cause the LED to burst.

After you have assembled and planned for all the three items follow these steps to wire your LED bar to the switch. 

  1. Make sure that the switch is in an “off” position to avoid any mishaps. Use copper wire to connect one side of a respective resistor to one terminal of the switch. Carefully solder both ends of this copper wire (to the switch and the resistor).
  2. Connect the other end of the switch to the positive side of your power supply, and the soldier both ends. Mark this end of the power supply with a positive ‘+’ sign.
  3. Use a wire to connect the cathode of the LED with the power supply and solder both ends.
  4. Turn the switch on an check if your LED lights.

How to Wire and Mount an LED Light Bar to Your Vehicle without Relay

Now that you have connected the switch to your LED light bar, you need to mount the light bar on your vehicle and wire the whole system together. 

What You Need

  • Driving light harness
  • LED light bar
  • Drill, bits, self-tapping screws
  • Socket sets
  • Electrical tape

Mount the Bar

The first step is to install your LED light bar on your vehicle bulbar, roof cage, or any other suitable sturdy location. You can also try to be creative with your mounting position.

Before you decide on all these, it is necessary to get familiar with your respective area regulations on installing driving lights. It might help you avoid unnecessary fights with the authority. You could incur hefty fines in some countries. 

Once you have identified the ideal place to mount your LED light bar to the vehicle, secure it firmly using the provided brackets.

Car with LED light bar

Disconnect Negative Terminal

Detach the wire from the negative terminal of your car battery before you do anything else. This safety-first move to ensure there are no injuries in the process. Disconnecting this terminal means that nothing else is on during this process. 

You could suffer from electric shocks. We recommend that you connect a memory reminder to your accessories to avoid losing your radio stations.

Mount the Switch

Identify a place in your car where the switch is easily accessible to you. You do not want to take your eyes off the road just to find a switch. You should mount it strategically inside the vehicle. 

Use the steps discussed above to wire your switch to the LED bar.

Carefully run the switch wires into the engine bay through an accessible grommet in the firewall.

You can do this by pocking the grommet with a sharp object. Be careful not to damage any wires when making these cuts on the grommet. You could also use an existing grommet with direct access to the engine bay.

Remember that our aim here is to avoid using a relay in our connection. Thus you will connect the wire that comes from the switch to your high beam LED. You can also connect it to the backup light cable. Connect the other wire to the ring terminal that must be earthed.

Connect You Two Harnesses

The most integral step after doing all that electrical work is using the remaining plugs to connect the two harnesses. The last connection should be that of the LED light bar to the circuit.

You should connect the single plug to the switch and connect the other to a power source that is earthed. This connection should be to the negative terminal of your battery. Or, it could be a bare metal bot with direct contact with the body of the care.

Get Your System Ready

This final step includes tidying up the system and ensuring safety. Tape-up any loose or naked wires and plugs.

After doing this, it is now time to reconnect your negative terminal to your battery. Double-check if you have done everything correctly before you test your LED light bar.

Car with LED light bar

Your light bar should be able to activate on the high. When you flick your light, the new LED light bulb should give you rays of blinding light.

This installation process requires expertise. If you are not sure about how to undertake it, you can contact a professional to help you with the wiring at a cost. Most manufacturers have their preferred mechanic to do this kind of job.

You could also pass by your regular mechanics and ask them to wire the LED light bar without a relay for you. This way, you are guaranteed it will work and, if anything goes south, they will be accountable.

If you are thinking about wiring your vehicle with LED light bars, then you might be in the right direction. Having this lighting system has proven to be a worthy investment over the past few years. It has also become stylish with vehicles like a jeep and other off-road riders.

Benefits of Having Light Bars

Before are some benefits of having LED light bars as opposed to the regular lights: 

  • They are more effective than traditional lights. Your in-built lighting system is not as powerful as LED light bars. The light that comes from LEDs is better illuminated. Because of this, people prefer then in offices and construction sites.
  • They are more energy and environmentally friendly. LEDs are one of the least energy consumers even though they give the best light. The fact that they do not produce much heat does not compromise their effectiveness.
  • The LED light bars have vast lighting options. Traditional vehicle lighting usually comes with spots. 
  • LEDs come with various lighting styles like auxiliary and cuticle. This aspect means that drivers have more options with this better technology.
  • They are safe. LED light bars do not emit any harmful substances when in use. Health experts have also acknowledged the benefits of this technology in trying to help save the environment.
  • They have a longer lifespan. 
  • One advantage is that they do not just stop functioning. Towards the end of the lifespan, LEDs do not just die; they warn you by being dim first. They give you time to plan for replacements.

Pros and Cons of LED Relay

Relays are essential in controlling the electricity in high-current circuit loads. But, you can always wire your LED without a relay. You can opt for alternatives like switches and circuits. Before deciding whether to avoid it or not, you must understand the pros and cons of doing so.

Advantages of Relay

  • A relay controls the electric flow in a high current circuit by providing low current ones.
  • Switches sometimes overheat. This overheating will happen when you wire your light bulb with switches as alternatives to relays.
  • Switches alone cannot handle the full current of the LED light bar in the absence of a relay. You will notice this problem in low powered LED bars. In high powered bars, this may become a nuisance. It may interfere with the efficiency of large switches. Hence, your wire may begin to melt or, the switches may overheat at the optimum level.

Disadvantages of Relay

  • A relay may sometimes cause ignition sparks between the switch contacts when the relay parts are vulnerable to extreme wear and tear.
  • They are irrelevant in the microelectronic circuit because of the low current: use circuitry instead.
  • Powering of the relay coil may with time damage as a result of back-emf.
  • Relays show a slow response. Because of this, they do not help turn the switch on and off at rapid speed. For this reason, some people will tell you to avoid relay.


Wiring an LED light bar without a relay in your vehicle may look simple. In a real sense, it is a complicated procedure. It requires that you have some electrical knowledge. Your LED light bar should operate on a high beam. If you do not wire it well, you could cause damages to the vehicle.