Working headlights are essential for driving any car safely, but they occasionally go out. Knowing how to change a headlight bulb and what to look for when the front of your car goes dark can help you quickly remedy the problem.
Why Do Headlights Fail?
Before we talk about changing your headlight, we should address the basics. Why do headlights fail in the first place? There are four common causes:
- Age. The most common culprit for a burned-out light is age. You could be driving and not notice that one of your headlights is out, and then, since the other one is the same age, within weeks that one might just go bad, too. Suddenly the problem becomes scarily apparent.
- Extreme temperature changes. As the temperature changes, your filament expands and contracts, further stressing it. A hard freeze followed by a warm day can significantly shorten your bulb’s life.
- Damage to the light housing. Halogen bulbs, in particular, are susceptible to moisture. If the headlight housing gets cracked, moisture and humidity will enter. You can install a fresh bulb in this situation, but it may blow out within a few days. Halogen bulbs are so sensitive that even the sweat from your fingers can cause them to fail. When installing a new bulb, handle it with rubber gloves to prevent this from happening.
- Oxidation. With newer halogen bulbs, another cause of dimming lights can be oxidation of the plastic housing, causing it to appear white or yellowish. This diminishes the beam of light that helps drivers to see the dark road ahead, he says. “In that case, you would have to replace the whole headlight assembly, he adds.
Is It the Bulb or A Fuse?
Your headlight has gone out. Do you go ahead and replace it immediately? First, you must determine whether you’ve got a blown bulb or an electrical issue.
With your car parked, turn on your headlights, and walk around to the front of the vehicle. Is one light out, or are they both out? If it’s one light, it’s probably a bulb issue. You’re most likely dealing with a blown headlight fuse if it’s both lights.
That’s good news since replacing a fuse is easier and cheaper than replacing a bulb! Wait until it’s light out, drive to any auto shop, and find the correct fuse.
If only one light is out, try banging on it with your fist. Doing this will jiggle the filament and can even (temporarily) fix the problem. You still want to replace your bulb as soon as possible. But this can buy you time to travel to an automotive shop safely.
How do you Check if the headlight bulb is out?
Determining the cause of a headlight issue begins simply by observing. First, put your headlights on to see if it’s just one light that’s out. If one is out, 90% of the time the light will go back on by simply replacing the bulb.
One quick test, if you don’t have a bulb handy or if you are out on the road when you notice the headlight issue, is to pull over and tap the light with your fist, which sometimes will make it go on.
If it goes on, that means the filament is burnt out. When you hit it, you’re shaking the filament and, if this makes contact, it actually lights up. This can at least enable you to make it to an area where you can have the light repaired.
When you’re selecting for bulbs your vehicle, think about:
- Throw distance or how far you can see down the road. One of the most important aspects for seeing better at night is looking ahead, being able to see twists and turns or obstacles in the road. Seeing farther gives you the chance to react more quickly in the dark.
- Color temperature. Some bulbs feature a warmer white, while some feature a cooler white. A cooler white will give you greater contrast and clarity – especially on reflective surfaces like road markings or road lines.
- Bulb life, or how long a bulb lasts.
Benefits of different bulbs
- Sylvania Basics are the longest-lasting bulbs on the shelf and they’ll closely match what came in your vehicle from the factory.
- XtraVision bulbs are rated for more down-road vision and longer throw distance.
- Silverstar bulbs pair more down-road vision with a cooler whiter light color.
- Silverstar Ultra gives the same Silver star white light with the farthest down-road field of vision of any Sylvania bulb.
- ZXE are incredibly powerful halogen bulbs that give the look and feel of an HID or LED system with no conversion kit and no worries about the bulbs being street-legal.
How To Replace Headlight Bulbs
Assuming your bulb is the issue, changing it is pretty simple. First, you’ll need to go to an automotive shop and purchase a replacement. As long as you know your vehicle’s make, model, and year, you’ll be able to find a new bulb in just a few minutes. Then, it’s time to replace it. Here’s how it’s done:
- Find gloves to wear. Oil staining is one of the main causes of premature burn out. Even one fingerprint on the glass of your bulb can cause it to burn out quickly. Avoid this by changing your bulb while wearing latex or vinyl gloves.
- Determine which headlight bulb you need. Your owner’s manual will tell you which kind of bulb your vehicle requires. It will also aid you in how to replace the bulb for your specific vehicle.
- Turn off your vehicle. It’s for your safety.
- Pop the hood and locate the headlight holder. It will be near the front of your car.
- Disconnect the power wires Usually, there will be three of them to disconnect. These are often held by a plastic catch, metal clip, or a screw cap.
- Remove the old bulb. In many vehicles, the back of the headlight holder can be removed, revealing the bulb. You may have to turn the bulb to free it from its socket.
- Replace with a new bulb. Remember to wear your gloves before handling the new bulb. It’s also a good idea to give it a cleaning before installation with and alcohol wipe. Place the bulb into the base and put the headlight holder back where you found it. Replace the wires that you took apart earlier.
- Test the bulb. Turn on your headlights to ensure that your new bulb is working properly. If it doesn’t work, double check your work and make sure you used the correct bulb. You may also have a wiring or fuse issue if everything seems correct. If you need help in determining what is wrong, seek help from a local mechanic.
If your replacement headlight bulb doesn’t work
Ultimately, if you replace a bulb and that doesn’t work, then you have to test the fuses and the wiring. If you have power going to the fuses and no power going to your light, you’re having a wiring problem. It could be that a wire broke somewhere, got pinched, or something like that.
Another thing to consider if you recently changed a halogen bulb is whether the replacement bulb was appropriate for your plug. Halogen bulbs today run very hot, and some car parts stores sell brighter or colored replacements over the counter that are touted as better for visibility but that run even hotter.
So, what happens with a stock OEM plug that the car came with from the factory is that it can’t handle this extra wattage. It starts to melt, and then it makes a bad connection and your light goes out. At that point you can’t even put a new bulb in, you have to change the whole light socket.