How To Repair A Dim Headlight?

Are your headlights leaving you in the dark? Dim, dead, or fading headlights are both terrifying and dangerous for drivers. Without proper repairs, you could find yourself facing a variety of problems, from a failed annual car inspection to serious accidents on the road.

Why are My Headlights Dim? 5 Problems and Solutions

Headlight Problem 1: Burnt Out Bulb

The most common problem that faces headlights is dim, dying, or burnt-out bulbs. Thankfully, this also comes with the simplest solution: bulb replacement. Much like the lightbulbs in your home, headlight bulbs need to be replaced every once in a while.

How can you tell when you need new headlight bulbs? In addition to noticing your headlights looking dimmer than usual, you can check for a burnt-out bulb with a few simple steps. Simply Park your vehicle in a safe space and turn on your headlights.

Then, step out of your car and check to ensure that both headlights are bright and functioning. When you notice one or both lights starting to dim, bring your car in for a bulb replacement service.

How To Repair A Dim Headlight

Headlight Problem 2: Lens Oxidation

Some drivers are surprised to learn that headlight dimming is not always caused by burnt-out bulbs. In fact, the lenses themselves may be to blame. Headlight lenses, the plastic pieces that cover the bulbs—are often made out of acrylic.

This material is known for chemically reacting with the sun’s UV rays. Over time, your lenses can become oxidized, leading to a foggy, cloudy, or yellowed lens appearance. The opaque shade caused by oxidation does not let as much light pass through as clear lenses. This will leave your headlights looking dim, even if you have brand-new bulbs.

The solution here is simple: headlight restoration service. Using professional-grade tools and experience, your mechanic can address lens oxidation and help protect your headlights from future troubles. You can read our full guide to headlight restoration service here.

Headlight Problem 3: Wiring Troubles

Your headlight bulb is illuminated by an array of electrical components. In most vehicles, this includes a wiring harness and a fuse. These components provide the power needed to fuel your headlights. Wiring troubles can cause your headlights to dim, misfire, or stop working entirely. Wiring troubles are rare, but not unheard of. They also become more likely if you have tampered with your headlights recently or attempted any DIY repairs.

This headlight repair will depend on the exact nature of your wiring troubles. You may need a wiring adjustment, a new wiring harness, a replacement fuse, or another electrical repair. An experienced mechanic can diagnose your headlight troubles and work with you to create a repair plan.

Headlight Problem 4: LEDs vs. Incandescent Bulbs

Have you ever driven past someone with blinding headlights? Even without the bright on, some LED headlights can seem much brighter than traditional versions. As such, if you are driving with traditional incandescent bulbs, you might begin to think your headlights seem dim in comparison.

Why are LED headlights so bright? According to the U.S. Environmental Protection Agency and the U.S. Department of Energy, LED lights can appear brighter than incandescent bulbs without providing any extra light. Why? Traditional headlights have a softer, warmer, sometimes even yellowish hue.

Meanwhile, LED lights emit a sharp white light with bluish tones. This color is harsher on the eyes, and it contrasts more starkly with the darkness of the night. As such, LED headlights can seem much brighter than incandescent bulbs, even when producing the same amount of light.

Of course, the brightness of a headlight will depend on other factors, including the vehicle make/model, the headlight lenses, the headlight shape, and more. Overall, the jury is still out on the effects of LED headlights.

  • The pros: Some drivers favor the energy efficiency and longevity of LEDs. They may also provide more visibility on the road for drivers.
  • The cons: Those opposed to LED headlights suggest that they cause more harm than good by creating a glare for other drivers, which could cause accidents and eye strain.

Regardless of your stance on LED bulbs, you can speak to your mechanic about alternative bulb options available for your vehicle if you are interested in brighter options.

Headlight Problem 5: Setting Configuration

Vehicles today often have several different lighting options for drivers to choose from. If you find that your headlights are too dim or have stopped working, take a moment to double-check your settings. Most new headlights adjust automatically unless they are otherwise configured.

As such, many drivers “set it and forget it.” When an accidental bump or guest driver adjusts your lighting, you might not think to check the setting configuration.

While it might seem obvious, there is a chance that you have your fog lights on instead of your standard headlights. In these cases, a simple adjustment of your headlight settings should get them working again.

How to Repair a Dim Headlight?

Simply clean the ground connection to restore the brightness of dim headlights. And apply a little dielectric grease. Or replace the bulb if you see a gray/brown film on the inside of the glass.

If your car has a headlight that puts out about as much light as a flashlight with weak batteries, we’ve got two simple fixes for you.

Most DIYers think they’ve got a bad headlight switch or a bad connection in the power feed. But most dim headlights are caused by a corroded ground wire. Just trace the wiring harness from the back of each headlight assembly and see where it connects to the vehicle body.

Another possibility is that as headlight filaments age, they deposit a gray/brown film on the inside of the bulb. Over time, that coating can reduce visibility by almost 300 ft.

If your headlights aren’t as bright as they used to be, yank one of the bulbs and look for gray or brown residue on the glass. If you find any, replace both bulbs now and get back to see more of the road.