How to Repair a Cracked Headlight

If you’re like most drivers, you don’t give much thought to your car’s headlights until one of them breaks. And if you’re like most drivers, you don’t know how to fix a cracked headlight. Fortunately, it’s a relatively easy repair that can be done with basic tools and knowledge.

How to Repair a Cracked Headlight

This blog post will show you how to repair a cracked headlight using the right supplies and following the right steps. We’ll also explain why fixing a cracked headlight is essential as soon as possible. Keep reading for all the details.

Summary: Headlight repair is a fairly easy process that can generally be done with materials found at most auto parts stores. The first step is to clean and dry the surface around the cracked headlight lens, then fill any cracks and holes in the lens by applying a resin kit specifically designed for headlight restoration.

After the resin set, it can be buffed using an appropriate polishing compound to make sure that the entire lens is covered and evenly polished. Finally, apply UV sealant to ensure maximum waterproofing of the repaired area.

8 Common Reasons That Causes a Cracked Headlight

1. Exterior Damage:

A crack on a headlight can occur if the light is hit by a pebble. The crack may start out small, but can become bigger over time. To fix the damage, the headlight may need to be replaced.

2. Overpressurization:

One common reason for headlight damage is overpressurization. If your headlights are looking more cloudy than usual, it might be time to replace them with a new set! Though they may not look damaged on the outside, over-pressurization can cause serious fogging and clouding on the inside that will make your light practically useless.

3. Temperature Fluctuation:

One common cause of cracked headlights is temperature change, especially if it’s a sudden, drastic shift. If you experience a drastic temperature change and notice hairline cracks, consider yourself lucky it could have been much worse! Take this as an opportunity to replace the headlights, and prevention is key.

4. Ultra-Violet Light:

Extremely intense ultraviolet light can cause your headlights to crack over time. The sun’s ultra-violet rays are so strong that they will eventually break down your headlight, causing it to have cloudy patches if you do not take precautions against it. Keep your headlights covered or replaced.

5. Age of Vehicle:

As with anything, your headlight will begin to weaken and become damaged from the natural wear and tear of everyday life over time. Replacing your lights after years of usage is normal, but if you aren’t having any problems with them, you may not need to replace them yet.

Replacing Lights After Years

6. Headlight Lens is Damaged:

A cracked or faded headlight lens can cause your light to dim more rapidly if exposed to unfavorable conditions such as rain, debris, or dirt. This type of damage can also occur over time from everyday life’s natural wear and tear.

7. Application:

If you own an older vehicle, its headlights may not meet the latest safety standards and be more susceptible to cracking over time. If you need to replace your entire headlight, take this opportunity to upgrade to brighter and more efficient headlights, such as an HID kit.

8. Running Over a Pothole:

If you find that your headlights are cracked after driving over a pothole, do not worry. The pothole’s impact is usually enough to cause tremendous damage and crack or break your headlight; however, it’s still possible for the shock from hitting the pothole to cause internal cracks within the light.

Step by Step Process: How to Repair a Cracked Headlight

Step 1: Assess the Damage to the Headlight

Before attempting to repair a cracked headlight, determine the extent of the damage.


  1. Inspect the headlight closely to identify the location and size of the crack.
  2. Determine whether the crack is superficial or has penetrated the headlight housing.

Step 2: Gather Necessary Tools and Materials

Gather the necessary tools and materials for repairing the cracked headlight.

Tools and Materials Required:

  1. Masking tape
  2. Sandpaper (600, 800, and 2000 grit)
  3. Clear headlight repair resin or epoxy
  4. Rubbing alcohol
  5. Microfiber cloth
  6. UV-resistant clear coat
  7. Plastic scraper or credit card
  8. Plastic gloves
  9. Bucket and water
  10. Hairdryer (optional)

Step 3: Prepare the Headlight for Repair

Before repairing the crack, properly prepare the headlight surface.


  1. Clean the headlight thoroughly with a microfiber cloth and rubbing alcohol to remove dirt, grime, and residue.
  2. Allow the headlight to dry completely.
  3. Apply masking tape around the perimeter of the headlight to protect the surrounding paint and trim.

Step 4: Sand the Cracked Area

Sanding the cracked area will help the repair resin or epoxy adhere to the surface more effectively.


  1. Wet-sand the cracked area using 600-grit sandpaper, dipping the sandpaper in water frequently to keep it wet.
  2. Sand in a circular motion, applying even pressure to create a smooth surface.
  3. Clean the sanded area with a microfiber cloth and water, then allow it to dry completely.

Step 5: Apply the Repair Resin or Epoxy

Apply a clear headlight repair resin or epoxy to fill the crack and seal it effectively.


  1. Put on plastic gloves to protect your hands from the resin or epoxy.
  2. Mix the repair resin or epoxy according to the manufacturer’s instructions.
  3. Carefully apply the resin or epoxy to the crack, ensuring that it fills the entire damaged area. Use a plastic scraper or credit card to smooth out the surface and remove any excess material.
  4. Allow the resin or epoxy to cure according to the manufacturer’s instructions. This may take several hours or longer, depending on the product and ambient temperature.
  5. If necessary, use a hairdryer to speed up the curing process, but be cautious not to overheat the headlight or surrounding components.

Step 6: Sand and Polish the Repaired Area

Once the repair resin or epoxy has cured, sand and polish the repaired area to blend it seamlessly with the rest of the headlight.


  1. Wet-sand the repaired area with 800-grit sandpaper, using the same circular motion and wetting technique as before.
  2. Clean the sanded area with a microfiber cloth and water, then allow it to dry completely.
  3. Repeat the wet-sanding process with 2000-grit sandpaper to further smooth and polish the surface.
  4. Clean the headlight thoroughly with a microfiber cloth and water, then allow it to dry completely.

Step 7: Apply UV-Resistant Clear Coat

To protect the repaired area and restore the headlight’s clarity, apply a UV-resistant clear coat.


  1. Apply the UV-resistant clear coat to the entire headlight surface, following the manufacturer’s instructions for proper application technique and drying times.
  2. Allow the clear coat to dry completely, then remove the masking tape from the surrounding paint and trim.

Step 8: Inspect and Test the Repaired Headlight

After completing the repair process, inspect and test the headlight to ensure that the crack has been effectively repaired.


  1. Carefully inspect the repaired area to ensure that it is smooth, even, and matches the rest of the headlight surface.
  2. Shine a light through the headlight to check for any signs of light leakage or distortion.
  3. Turn on the headlights and check that they are functioning properly and without any issues.
  4. Test the headlight in different lighting conditions to ensure that the repaired area does not affect visibility or cause glare.

By following these detailed steps and using the appropriate tools and materials, you can effectively repair a cracked headlight and restore its functionality and appearance. Remember that the success of the repair depends on the extent of the damage, the chosen repair method, and your DIY repair skills. If you are unsure about any part of the process or encounter any difficulties, consult a professional mechanic for assistance or consider purchasing a replacement headlight.

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Some Helpful Tips to Maintain Your Headlights

Now that you know how to repair a cracked headlight, here are some tips for maintaining them.

1. Keep your headlights clean. If the lenses of your lights become dirty or foggy, then less light will be shined onto the road.

2. Don’t let water build up on the lenses of your lights. Water can accumulate and eventually pool and cause damage to your headlight assemblies over time.

3. Avoid head-on collisions with larger objects. This will reduce the possibility of your lights being damaged if they are struck directly by an object.

4. Don’t drive with high beams on constantly. Constant use of high beams can contribute to faster degradation of headlight lenses over time.

Don't Drive With High Beams

5. Keep your headlights properly aligned. Improper alignment may cause uneven distribution of light at night.

6. Don’t drive with headlights off for extended periods, such as during the day when the weather is clear and sunny. This can accelerate headlight deterioration. If you must drive without your lights on, dip them to prevent higher temperatures from building up and causing damage to lenses and bulbs (if your car allows you to do this).

7. Don’t forget to replace old light bulbs with higher-efficiency ones. If one of your headlights is not illuminating properly, you may have a burned-out bulb or headlight assembly.

Should You Drive With Cracked Headlight Lens

Headlight lenses are made out of plastic that can become very brittle when exposed to extreme heat and ultraviolet rays from the sun. This means that over time, they will crack from exposure without warning. These cracks can appear very suddenly when driving, so it is essential to be aware of this problem and what you should do if it happens to you.

The primary reason car owners are discouraged from driving with a cracked headlight is that it can cause the lens to shatter on impact, especially on highways or high-speed roads. Even though plastic is durable, driving over debris on the road at sixty miles per hour can quickly result in tragedy.

The good news is that damage to the lens can often be repaired by filling in cracks with a special plastic resin compound. If you have never done this before, some professionals perform this service for car owners every day.

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Frequently Asked Questions

Can Headlight Plastic Be Repaired?

Headlight plastic may not be able to be repaired, depending on the severity of the damage. If there is only minor damage, a sealant may be able to fix it. However, if there is significant damage or the headlight has been broken off completely, then a new headlight may need to be purchased.

What Kind of Plastic Is for Headlights?

There are many different types of plastics that can be used for headlights, including PET (polyethylene terephthalate), PAHS (paramagnetic high-density polyethylene), and PMMA ( polymer modified methyl methacrylate). Each has its own advantages and disadvantages, so it is important to choose the right one for your needs.

PET headlights are often considered to be the most durable because they resist scratches and fading. They also have a longer lifespan than other types of plastic headlights.

PAHS headlights offer better light distribution thanks to their large surface area, but they tend not to last as long as PET or PMMA lights due to their susceptibility to rain damage and cracking.PMMA headlights are commonly used in luxury cars due to their glare-free lensing ability and resistance to UV radiation.

Is a Cracked Headlight a Mot Failure?

Cracked headlights are one of the most common light problems on cars. Mot failure is the technical term for when a headlight fails to meet the required performance standards.

There are a few things you can do to address cracked headlights:

  1. Replace the headlight – If it’s determined that the cracked headlight is causing actual mot failure, it may be necessary to replace the headlight. This is typically done at a cost of around $100-$200.
  2. Repair the headlight – If it’s determined that the crack simply requires a repair, this can be done by replacing the lens and/or surface reflector. This repair typically costs around $50-$100.
  3. Adjust the light output – Sometimes adjusting light output can help mitigate or eliminate mot failure caused by cracked headlights. This typically requires a trip to a mechanic and can cost around $100-$300.

Why Does My Headlight Bulb Keep Breaking?

Headlight bulbs are one of the most commonly replaced components on a car, and for good reason. They’re essential for Parkway visibility both during the day and at night, and they also play an important role in reducing your risk of getting hit by a car.

However, headlight bulbs can also be expensive to replace, so it’s important to take care of them in order to ensure their long-term durability. One way to do this is to make sure that you keep your headlights clean by using a light dusting before each use.

Additionally, make sure that you replace your headlight bulb regularly (every 12 years), even if it doesn’t seem necessary based on how often you drive or park your car. This will help minimize the chances of it breaking again down the road.


Headlights are an essential part of a car. They help you see in the dark, but they also let other drivers know your intentions. Driving without headlights is illegal in many states, so it’s essential to understand how to repair them if they crack or break.

In this blog post, we have discussed how to repair a cracked headlight using simple materials that you can find at home. If you have any questions or want to know more, then feel free to comment below. To find out more about other car repairs, follow our blog for updates on the latest automotive trends!

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