One Headlight is Dimmer Than the Other

One of the headlights on your car is often dimmer than the other side. This guide looks at common problems that cause one headlight to be dimmer than the other.

Symptoms

• One headlight is dim, and the other is bright.
• One headlight is dimmer than the other side.

Common Problems

Bulb Age

A dim headlight on one side is usually caused by a light bulb that has reached the end of its life.

Wrong Light Bulb Wattage

In cars with HID Xenon headlights, it is common for one of the headlights to be dimmer than the other. This is often caused by an HID bulb reaching the end of its life.

Bulb Not Installed Properly

One bulb may be dimmer than the other due to a bulb not being installed. If the bulb does not sit correctly in the headlight socket above, the headlight will not project the light correctly, making it look dimmer than the other side.

Headlight Misaligned

This is a common problem after an accident. The headlight assembly may be misaligned, causing the beam to point too low making one headlight look dimmer. All headlights can be adjusted.

Foggy Lens

A foggy lens may also be why one headlight looks dimmer. This could be an issue if you replaced one headlight assembly but not the other. Use a headlight restoration kit to restore the foggy headlight to like-new condition.

What should I do if one headlight is dimmer than the other?

First, find out if the headlight bulb was recently changed. It may have been changed with a bulb with different color temperatures, making it appear different or dimmer than the other headlight.

Headlight Brighter / Dimmer	Headlight Different Color
Bulb reaching the end of life	Different Bulbs
Weak Ballast	Bulb reaching the end of life
Poor connection or ground

To fix the problem where one headlight is dimmed or brighter than the other, you will need to remove the dim bulb and replace it. If that doesn’t fix the problem, check the bulb’s voltage. A short or poor ground can cause the voltage to be less than 12 volts.

We hope you find the One Headlight is Dimmer Than the Other guide helpful. Check these troubleshooting and repair guides for more help on your vehicle.