A burned out low beam can make it difficult to see at night, and driving with your high beams all the time can make it difficult for other drivers to see. Fortunately, fixing a poor low beam is a straightforward process on most vehicles that can be accomplished by many people with a few hand tools. If replacing the bulbs doesn't work, there may be an electrical problem with the vehicle that needs to be checked by a professional.
Part 1 of 3: Preparing to Replace a Low-Low Light Bulb
Step 1. Identify a burned out light bulb
You can usually tell when a headlight burns out while driving, but confirm which bulb actually burned out by leaving the headlights on and getting out of the vehicle to check. Then return to the vehicle and turn on the high beams. Some cars use a single bulb for the high and low beams, while others do not. If the high beam on the same side is off, it may be a light bulb.
- You don't have to buy specific bulbs for each side, but identifying which one is burned out will help you replace it without having to start the vehicle again.
- If neither of the high or low beams are working on the same side, there could be an electrical problem preventing the bulbs from receiving power.
Step 2. Buy a replacement bulb
It is important that you purchase the correct bulb for the year, make and model of the vehicle. Ask your local auto parts store clerk to look through the system, or try checking the automaker's website for the code that indicates which headlight to use.
- Headlight codes are usually made up of letters and numbers like H11B or D3S.
- You can find the correct code for the vehicle on websites such as www.lightbulbs4cars.com.
Step 3. Gather the necessary tools
Changing a low beam bulb can require different amounts of work. While some cars may not require any tools, others require specialized tools to help remove parts of the trim under the hood or even the bumper and grill. See the service manual for the specific vehicle for a complete list of tools needed to get the job done. Most vehicles require only a screwdriver or nothing to access the headlight housing.
- After consulting the service manual for the vehicle, visually inspect the area around the headlight to make sure it looks the same as in the manual.
- If you bought a used vehicle, the flat head screws may have been replaced with Philips head screws or other components have also been changed during repairs by the previous owner.
Step 4. Disconnect the battery
Make sure you remember which side of the car has a burnt out low beam before disconnecting the battery. To disconnect it, use an appropriately sized hand wrench or socket wrench to loosen the nut that holds the ground wire to the negative post of the battery. You don't have to remove the nut, just loosen it enough to pull the cable out of the post, then tuck the cable into the side of the battery.
- By inserting the cable, you will prevent it from jumping out and coming into contact with the negative post of the battery.
- You will have to disconnect the positive terminal.
Part 2 of 3: Remove the old light bulb
Step 1. Remove the necessary trim pieces
On many vehicles, you will need to remove a piece of trim that separates the headlight assembly from the engine compartment. Usually this piece of plastic extends the width of the car, but in some there may be individual pieces for each headlight. On some newer GM vehicles, you may also need to remove the bumper cover to access the headlight assemblies.
- Consult the service manual for the specific vehicle to better understand which parts of the vehicle must be removed to access the headlights.
- Be careful not to break the plastic fasteners or snaps the vehicle uses to hold the trim pieces in place.
- Replacement fasteners or clips of most types can be purchased at your local auto parts store.
Step 2. Locate the lighthouse holder or container
Many newer vehicles use a plastic headlight housing to hold the bulb in place, while others use a metal or plastic bracket. Use your vehicle's service manual to locate the bracket or container, then remove the headlight and coil cord from it. On many vehicles, you will only need to turn the headlight a quarter turn to the left and pull it back to remove it.
- If you need to remove any screws from the headlight assembly bracket, be sure to keep them in a safe place until you reassemble that part of the car.
- On some vehicles, you will have to unscrew the headlight assembly and remove it from the car to access the bulb in the back.
Step 3. Disconnect the wires going to the headlight
The headlight bulb should still be in the bracket connected to the wiring coming from the vehicle. Disconnect the cables by unhooking them from the bottom of the headlight housing and gently pull to disconnect it. Make sure to pull the plastic clip and not the wires, as you could accidentally pull them out of the bulb housing, causing the headlight to not work.
- Be careful when unhooking the clamp. It is usually made of brittle plastic and can break easily.
- If you break the clamp, you can either secure it in place with a single strip of electrical tape, or purchase a replacement welding clamp instead of the old one.
Step 4. Pull the headlight bulb out of the housing
Place your index finger and thumb as low as possible on the base of the bulb and pull it out of the housing. Don't pinch the larger part near the top of the bulb as it can crack or break and cut you. A broken light bulb is significantly more difficult to remove.
- If you break the bulb, use a pair of pliers to remove what is left in the housing.
- Dispose of the burned-out light bulb in the trash once it is complete.
Part 3 of 3: Install a new headlight bulb
Step 1. Remove the bulb from the package with gloves or a tissue
The oil on your hands can affect the glass of the bulb, reducing its life. Prevent this from happening to him by wearing gloves or a tissue every time you come in contact with the glass of the new low-beam bulb. Be careful not to throw it away while removing it from its package.
If you touch the bulb, use rubbing alcohol and a paper towel or rag to clean it
Step 2. Slide the new bulb into place
Keep your gloves on or grasp the bulb with a tissue as you slide it into the housing. Be careful not to press too hard on the top of the bulb to prevent the glass from cracking or breaking. Make sure to firmly place the bulb in the housing so it has a solid electrical connection.
- You may need to press down on the top of the bulb to make it fit properly, just be careful not to press too hard.
- If you feel like you have to force the bulb, it may not be the correct one for the vehicle.
Step 3. Connect the wiring to the bulb assembly
Take the coil cord that you disconnected from the bulb earlier and reconnect it to the back of the assembly with the new bulb in place. Make sure the clip snaps into place and holds the coil cord firmly. If the cables come loose while driving, the headlight will stop working.
- In this step, the headlight bulb and assembly need to be connected to the car again.
- Be careful not to pull on the assembly when connecting, as you could rip a wire out of the harness.
Step 4. Slide the bulb assembly back into the housing
Clean the bulb again with rubbing alcohol if you feel like you've touched it to your skin, then slide it into the housing. Either turn the bulb assembly a quarter turn clockwise to secure it, or reinstall the bracket that holds the headlight bulb in place.
- Pull the headlight bulb assembly once you are sure to know that it is securely in place.
- Make sure to use the same screws you removed to secure the mount if it has them.
Step 5. Reinstall the parts and reconnect the battery
With the headlight completely reassembled, replace the parts you removed in the opposite order in which you removed them. Many pieces overlap, so it is important to put them back in the correct order.
- Reconnect the battery once the trim has been reassembled.
- Turn on the headlights and check to make sure the bulb is working.