How to Change Headlight Bulbs: 6 Easy Steps + 4 FAQs

You’re driving, and it’s getting dark. So you decide to turn on your headlights.

But oh no, it’s not working!
You need them replaced ASAP.

Want to know how to change headlight bulbs on your own?

Well, you’ve come to the right post! We’ll explain how to change the headlight and answer some FAQs about the headlight — like why it fails and how often it should be replaced.

This Article Contains

How to Change Headlight Bulbs (Step-by-Step)
Types of Headlight Bulbs and Housings
4 FAQs About Car Headlights

Time to switch the lights on.

How to Change Headlight Bulbs (Step-by-Step)

Changing headlights can be easy or difficult, depending on how your headlight housing is set up. But with some patience, you should be able to get it done.

Before you change your headlights, you need to decide what headlight bulbs to get.

TIP: Also, you should conduct a quick fuse test, to make sure the headlight is the real problem and not a faulty fuse. A blown fuse can sometimes cause faulty or dim headlights. So finding out whether it’s a fuse or light bulb issue earlier can help you save time and money.

If your fuse is A-OK, and you have your new bulbs set aside, here’s what you need to do:

Turn your vehicle off.
Locate the headlight housing and disconnect the wiring harness.
Remove the housing and unscrew the old bulb.
Insert the new bulb and reattach the headlight housing to the electrical connector.
Repeat the procedure for the other headlight.
Test your new headlights.

Here’s a more detailed guide:

Step 1: Park in a Well-lit Area and Turn off the Engine

Park your vehicle on a flat, well-lit surface, and engage the parking brakes. Turn off the engine and remove the keys from the ignition.

Step 2: Open the Hood and Disconnect the Headlight Housing

Open your hood and disconnect the negative terminal on the battery— to avoid touching a live wire. Next, locate the headlight backing behind the housing. Unscrew the dust cover and disconnect the power connector before removing the headlight housing unit.

(Some headlight housings may not require removal, and you’ll have to access them directly from behind — through the engine bay or from the wheels.)

Disconnect the power connector by releasing the metal clip or screws attaching the power wires to the bulb. Use a Phillips screwdriver to pry a hard-to-remove metal clip. Sometimes you might also have to remove other components, like the battery or air filter housing. In some cars, you’ll also find a screw cap covering the electrical connector. Just remove it before releasing the power connector from the bulb.

Once you’ve removed the entire headlight assembly, time to replace the bulb from the headlight holder.

Step 3: Unscrew the Old Headlight Bulb

Before unscrewing the bulbs, in older vehicles, you’ll need to identify which headlight bulb is the low beam and the high beam.

A new vehicle uses one light bulb for both. The bulb in a new car has two individual filaments, one for the low beam and the high beam lights.

If your vehicle uses two bulbs, here’s how you can distinguish them:

The low beam bulb is typically on the outer side of the headlight, while the high beam is on the inside.
The low beam bulb has a higher part number than the high beam. To find the part number refer to the owners manual.

After taking note of the bulb placement, you can remove them from the bulb holder. Grab the bulb and turn it counterclockwise.

Notice how the locking tabs behind it turn as well?

Pull out the old bulb once the tabs are aligned. Be careful when removing the old headlight bulb from the bulb holder, and don’t ruin the locking tabs. Because once they’re damaged, you’ll have to replace the entire headlight assembly.

But if your car uses a sealed beam headlight, you’ll have to remove the screws that connect the glass cover to the body. Use a Phillips screwdriver to slowly pry off the glass cover once all the screws are off. Only after that can you unscrew the HID headlight bulb.

Step 4: Screw in the New Headlight Bulb

Set aside the old bulb and prep the new bulb.

Handle the new bulb with gloves or wrap it in tissue paper. This prevents you from accidentally contaminating the new headlight bulb with oils or water, as it could reduce the light bulb’s life span.

Line up the replacement bulb with the locking tabs on the headlight holder and turn it clockwise until it clicks. If needed, gently wipe the bulb clean.

Reattach the headlight assembly to the car’s body. Be sure to connect the other components you have removed.

Step 5: Repeat Steps 2 to 4 on the Other Headlight

When replacing a headlight bulb, you should change them out in pairs. Usually, when one bulb dies out, the other isn’t far behind.

Simply repeat steps 2 and 4 with the headlight on the other side.

Step 6: Do a Quick Test

With your new headlight bulbs in, turn the car back on, and test them out. Cycle through the high and low beams to ensure they work properly.

If it’s all good, your car is ready for the road!

However, if you notice something wrong with the new bulb— they appear dim, don’t come on, or the check engine light illuminates, it’s best you take your car to the mechanic. Frayed power wires or a faulty wiring harness could be the culprit. Your mechanic will have to check and figure it out.

Remember that you need to check on the type of headlight your car uses before changing them?
Let’s look into that.

Types of Headlight Bulbs and Housings

You should determine the type of bulb and headlight housing unit your vehicle has to ensure you get the correct headlight replacement bulb for your car.

A. Types of Headlight Bulbs

There are a few different headlight replacement bulb options.
Here are the three main types of headlight bulbs:

Halogen bulbs: Halogen lights contain halogen gas and a tungsten filament in the bulb and produce a yellow-tinged light. A halogen bulb can last from 450 to 1700 hours.

LED bulbs: This bulb produces light by passing an electric current through a microchip. LED bulbs produce a cool bright light that lasts for 10,000 hours.

HID lights: These headlight bulbs produce light as bright as a LED headlight. The glass bulb gives off a cool white or blue light when heated. HID lights last longer than halogen lights but not as long as LED bulbs.

Different headlight assemblies need different equipment and extra steps when replacing them. If you need to change your entire headlight assembly, you might want to know the types of available headlight housings as well.

B. Types of Headlight Housing

Let’s explore some of the most popular headlight housing options:

Reflector Headlight Housings: Uses a reflective surface to direct and focus the light.

Projector Headlight Housings: Combines a small reflector and a convex lens to provide a precise and intense light beam.

Composite Headlight Housings: Also known as sealed beam headlights, it integrates the bulb, reflector, and lens into a single glass unit.

LED Headlight Housings: Offers various designs with individually controlled small LEDs for precise lighting patterns.

HID Headlight Housings: Equipped with projector-style housing to control light output and minimize glare.

Now that you have the basics of changing headlights, time for some FAQs.

4 FAQs About Car Headlights

Here are the answers to some common questions about headlights:

1. What Are the Signs of Failing Headlights?

These signs point to headlight failure:

Dim headlights: Your headlight bulb can dim out over time. However, if it’s due to a weak battery, or a bad alternator, your check engine light or battery warning light will pop on.

Flickering headlights: This happens when the filaments inside the bulb start to go bad or are excessively worn.

Only one headlight works: Regular use or a blown fuse can cause one headlight to burn out and stop functioning.

Both headlights won’t work: This one’s an obvious sign to get it changed. Do we have to explain more?

Faulty headlights reduce visibility and can endanger other road users. So, replace your headlights if they show any of these signs.

2. Why Do Headlights Fail?

Headlights can fail for several reasons, like:

Old age: Headlights, like other electrical devices, can wear out over time.

Extreme temperature changes: Sudden temperature changes can shock the glass casing of the bulb and take a toll on the bulb’s filament.

Damage to the headlight assembly: Huge scratches or even yellowing of the headlight casing can cause the bulb to die out faster, especially with halogen bulbs.

3. How Often Should I Replace My Headlights?

On average, you should get a headlight bulb replacement every 2,000 to 3,000 hours of use—usually after 7-10 years.

4. How Do I Conduct a Fuse Test for My Headlight?

Here’s how a mechanic would conduct a fuse test:

Locate the fuse box based on the owners manual— some cars have it inside the engine compartment, while others store it inside the car on the driver’s side.

Open the fuse panel cover, read through the codes inside the panel cover, and find the code for the headlight fuse— if not stated, refer to the owners manual.

Locate the fuse for the headlight and test the pin connectivity using a multimeter.

A functional fuse will cause a positive reaction from the multimeter, producing a constant sound. If the multimeter remains silent, the fuse is broken and needs to be replaced.

Final Thoughts

Regularly replacing headlights is crucial for optimal visibility and ensuring your safety on the road. Learning to change them independently is a good skill, and you can save some cash.

However, if you’re unfamiliar with auto parts and need a headlight bulb replacement for your vehicle, call in the professionals— like RepairSmith!

RepairSmith is a mobile auto repair service that you can easily get in touch with by filling out an online form. Our technicians are equipped with all the tools needed to fix any automobile issues you have.