How to Replace a Headlight Assembly

The headlight lens assemblies on your vehicle are vital to your safety. These parts are responsible, along with the headlight bulbs themselves, for increasing your visibility while driving in the dark or in poor weather conditions. Your vehicle’s headlight assemblies house the headlight bulbs,and feature a clear headlight lens designed to protect your headlight bulbs against damage. The headlight lens shields the bulbs against debris and other harmful elements, such as insects, dirt, dust, and more that could break the bulb or cause premature wear. Headlight assemblies may also house the turn signal or marker light bulbs, which are necessary to drive your vehicle legally and safely.

Over time, your vehicle’s headlight assembly lenses can become foggy or chalky, resulting in impaired visibility. This cloudy appearance on the headlight lens is usually caused by oxidation from sun exposure or debris buildup that causes an uneven lens surface. Headlight assemblies may also leak, and water that enters the assembly can evaporate and cause condensation behind the lens. Driving your vehicle in low-light conditions with a damaged headlight lens or headlight bulb can be dangerous, as it not only reduces your visibility, but can also prevent your vehicle from being seen as easily by other drivers. If your headlight lens assembly is damaged, or if your headlights are dim, you may be able to perform a headlight restoration before completely replacing the assembly. Headlight restoration allows you to sand and polish out chalkiness or fogginess in the headlight lens, but would not be applicable for a broken or severely damaged lens. No matter what sort of damaged it has experienced, it is important to repair or replace the headlight assembly as soon as possible to maintain your safety on the road.


Additional Resources

Tools & Materials

Safety Glasses Safety Glasses
Gloves Gloves
Power Torque Tool Set Tool Set
Plastic Trim Tools Plastic Trim Tools
Headlight Assembly Headlight Assembly

Step-By-Step Instructions to Replace a Headlight Assembly

Cloudy or damaged headlight assemblies can make it difficult for you to see while driving in low-light conditions, and can make it more difficult for other drivers to see your vehicle on the road, which can put you and others in danger. Our detailed instructions can help you perform a headlight assembly replacement on your vehicle to keep you safe in any weather or at any time of day. It’s not uncommon for a vehicle to have panels or parts that need to be removed in order to change headlight assemblies. The procedures to replace a headlight assembly are usually simple and straightforward, but can be time-consuming or more difficult on some vehicles. The steps below demonstrate a headlight assembly replacement on a 2003 Pontiac Grand Prix, but procedures will vary from one vehicle to the next, so make sure to check your vehicle’s service manual for specific information before starting this repair. If you’re not completely comfortable doing the job yourself, we’d also be happy to recommend a professional technician.

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A gloved hand uses a socket wrench to remove the headlight assembly hardware.

Step 1: Remove the Headlight Assembly Hardware

Open the hood to access your headlight assembly. On this vehicle, we’ll locate the two bolts on the top of the assembly and remove them with a wrench or socket and ratchet. Other vehicles may have bolts across the top or side of the assembly, and it’s important to be certain you’ve removed all of the retaining hardware before attempting to remove the assembly.

Do It Right: Place your bolts somewhere safe so that you don't lose them. Our parts professionals recommend a magnetic bowl designed to keep metal parts in place and prevent them from being misplaced.

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A gloved hand removes the vehicle's old headlight assembly.

Step 2: Remove the Old Headlight Assembly

After the bolts are removed, you should be able to gently slide the entire assembly out enough to release the headlamp bracket tabs from their slots on either side of the assembly. This may require significant pressure on some vehicles, and it may also be a good idea to utilize a plastic trim remover tool or other non-marring prying tool to prevent damage to the paint.
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A gloved hand disconnects the old headlight assembly wiring from the vehicle.

Step 3: Disconnect the Headlight Assembly Wiring

Carefully slide the headlight assembly out and disconnect the electrical connectors from the headlamp and parking or turn signal light sockets.On some vehicles, there may be a single connector, or it may make more sense to remove the bulb sockets to free the assembly from the wiring harness. More on that in the next step.
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The headlight bulb sockets are removed from the vehicle.

Step 4: Remove the Headlight Bulb Sockets

Turn the headlamp retainer ring counter-clockwise to disengage and remove it from the head light assembly. After the retainer ring is removed, remove both bulb sockets from the headlamp assembly. In our case, we’re also moving the headlight wiring harness to the new assembly, so we can disconnect the electrical connector from the body wiring.
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The old headlight assembly wiring harness has been removed.

Step 5: Remove the Old Headlight Assembly Wiring Harness

Remove the screw on the top of the headlight assembly, located between the headlamp and parking light in order to fully remove the old headlamp wiring harness.
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The Headlight Assembly Wiring harness is transferred to the new assembly from the old one.

Step 6: Replace the Headlight Assembly Wiring Harness

Transfer the headlamp wiring harness to the new assembly by removing the screw to make room like we did on the old assembly.
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A two image split of the bulb sockets being installed.

Step 7: Install the Bulb Sockets

After securing any new bulbs in their sockets, they can be inserted into the new assembly. Secure the headlamp socket by turning the retainer ring clockwise onto its socket. Reinstall and reconnect the electrical connectors to the headlamp and parking light sockets.

Do It Right: If reusing the old wiring harness, bulb sockets, or bulbs, check each of these items for signs of damage or corrosion before installing the new headlight assembly.

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A two image split of the new headlight assembly being installed.

Step 8: Install the New Headlight Assembly

Position the assembly so that the bracket tabs are aligned with their slots. Slide the headlamp inward to engage the tabs. Then reinstall the two bolts at the top of the assembly to secure it in place.
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A new headlight assembly is lit for the first time after vehicle installation.

Step 9: Test Your Headlights

After your new headlight assembly is installed, turn on your headlights and other lights to make sure they are working properly.
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Step 10: Repeat the Process

If you’re replacing both headlight assemblies, repeat these steps on the other side.


Replacing Your Headlight Assembly with Parts and Tools From O’Reilly Auto Parts

Find the parts and tools you need to complete your headlight assembly replacement at O’Reilly Auto Parts. We carry the headlight lenses, headlight assemblies, and replacement headlight bulbs you need for your headlight repair. O’Reilly Auto Parts also offers free headlight bulb installation, as well as tail light bulb, turn signal light bulb, and brake light bulb installation on most vehicles.

Additional Resources

New Headlight Bulb on Car

How to Change a Headlight Bulb
Headlight Lens Restoration and Cleaner

How To: Headlight Restoration
Additional Resource - How to Fix Dim Headlights

How to Fix Dim Headlights
How To Install Tail Lights On Vehicle

How to Replace Tail Light Bulbs

The automotive repair work depicted in this series is performed under the direction of the manufacturer of the product featured. Prior to undertaking any of the demonstrated repairs on your vehicle, we suggest you consult with a certified mechanic or another professional who can adequately advise you of the proper repair or remedy required. O’Reilly Automotive Stores, Inc. and its affiliates (“O’Reilly”) disclaims any responsibility for injury or damage resulting from a viewer’s attempt to recreate the repairs shown in this series.