Why Does My Light Bar Only Work on Low Beams?

When driving at night, particularly on off-road safety, a light bar is an absolute must-have component of automobile safety equipment. Additionally, they are very beneficial even in the daylight during the winter months when the weather is hazy in locations where eyesight is impaired.

You will be protected from any traffic risks or disasters because of the increased road visibility.

These are durable, simple to mount, brilliant, and need little maintenance. The advantages of light bars include enhanced eyesight and brightness, which makes them an excellent complement for drivers who travel in low-light conditions.

Although, based on where you reside, you may be unable to utilize light bars on the highway due to regulatory constraints.

Why Do You Buy a Light Bar?

Whenever it concerns seeing at dark in off-road situations, ordinary factory headlights aren’t always up to the task. When the landscape is difficult to navigate, it is critical that you have adequate light to see clearly there next to you, particularly if there is wildlife around or in foggy weather.

Because of this, many off-roading vehicle owners choose to install light bars on their cars. It is necessary to provide more light in these difficult settings. Light bars are incredibly popular because they provide wide coverage and come in a variety of sizes that are suitable for a variety of cars and traveling circumstances.

Why Does the Light Bar Only Work on Low Beams?

A light bar works perfectly on low beams compared to high beams.  It is unlawful to drive on the highway while using a light bar because of the brightness of the light bar. In fact, in most states, merely turning them off isn’t enough of a deterrent. While the car is being driven on the highway, it is necessary to utilize a light cover.

These covers guarantee that even if the lights are accidentally turned on while driving, they will not be a distraction for approaching cars. Consequently, even if the light bar is being used on the road, it should be illuminated utilizing the low beams of the bar lights rather than the illegally high beams of the bar lights. In addition, if it does not, we have procedures on how to fix it below.

Procedures If the Light Bars Don’t Work on Low Beams

1) First and foremost, you must verify the circuit, and if you discover that the relay is being activated by the low beam circuit, you should be aware that the relay will only be powered when voltage is provided from the high beam circuit, as previously stated.

2) Configure the plug and play wire harness in the car such that the light bar only illuminates when the low beam headlights are turned on.

3) If the light bar does not function, look at the wiring harness to see if you need to modify any wires surrounding the light bar assembly to ensure that the relay shuts when the light bar is on a low beam.

Trace the relay trigger wire back to the positive battery terminal and then back to the negative battery terminal to determine where the wires are. Then all you have to do is locate the positive high beam cable.

4) When using a high beam, if the improper trigger is used, it will not always function properly. Instead of using the high beam to trigger the relay, the low beam is used. Only the trigger wire has to be changed in order for the light bar on the low beam to function well when installed in the car.

5) Plug & Play wiring harnesses are intended for positive switching headlights; if your vehicle has negative switching headlights, it may sometimes fail to function properly, particularly on high beam mode.

As soon as the low beam circuit is turned on, the trigger cable will get 15V from the high beam filament, and as soon as the low beam switch is turned on, the high beam circuit will be turned on, and the trigger cable will be pulled to grounding.

6) Simply remove a connection from the rear of the h4 connector, at the point where it connects to the front light bar lighting. With a multi-meter, you can determine which one is a high beam or a low beam.

Connect that cable to the coil; if the coil’s negative is being swapped, you may want to consider replacing it with a permanent negative that is coming from the assembly in some way.

As you can see, the light bar operates on a low beam and is also simple to set up. If the light bar does not function, follow our detailed to-do processes above for instructions on how to repair it.

Key Features of a Light Bar


Because light bars are formed up of many individual lights, the size of the light bar has a tendency to impact how brilliant the light is and how much visible area it illuminates.

Because most light bars are rectangular horizontal flat bars in shape, you need to take into account the height and breadth of the light bar you want to install.


Because the majority of light bars are utilized in off-road environments, they need some level of resistance to the elements, such as watertight and weatherproof protection, in order to perform efficiently.

Mounting Alternatives

It is necessary to physically connect a light bar to a vehicle in order for it to be of any use. This is somewhat determined by the mounting points that are accessible to you. The majority of light bars are designed to be attached to additional accessories such as roof racks.

Final Note

These light bars, which are available in both beam and deluge patterns, will enable you to notice barriers much before the original head lighting system illuminates them.

Adding a light bar to your vehicle should be high on the priority list if you want to spend significant time off the established path, particularly during low-light situations on the highway.

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