Replacing a headlight is usually a job you can do yourself in 15 to 30 minutes, though the exact process depends on your vehicle's make and model

Most headlight failures are bulb failures, not electrical problems. The bulb burns out, you replace it, and you're done. Some cars make this straightforward—pop the hood, twist the bulb socket counterclockwise, pull it out, and insert the new bulb. Others require you to remove the entire headlight assembly, which means unbolting plastic trim and disconnecting wiring harnesses. A few luxury or newer vehicles have sealed headlight units that can't be serviced at home and need a shop visit.

Before you start, check your owner's manual or search your vehicle's year, make, and model online to see which type you have. This takes five minutes and saves you from buying the wrong bulb or discovering halfway through that you need a socket wrench set you don't own.

Key Takeaways

  • Most headlight bulb replacements take 15 to 30 minutes and cost $15 to $50 per bulb, depending on bulb type and whether you do it yourself or pay a shop.
  • Your owner's manual or a vehicle-specific repair guide will tell you whether your headlights are user-replaceable or require professional service.
  • Halogen bulbs are the most common and cheapest; LED and HID bulbs last longer but cost more and may require additional wiring or calibration.
  • Always replace both headlights at the same time, even if only one has failed, to keep brightness and color temperature matched.
  • If your headlights are dim but not burned out, the problem may be a corroded connector, a failing alternator, or a battery that's not holding charge—bulb replacement won't fix these.

What type of bulb your car uses

The three common headlight bulb types are halogen, HID (high-intensity discharge), and LED. Halogen bulbs are the oldest and cheapest—they cost $15 to $30 per bulb and last 500 to 1,000 hours. HID bulbs are brighter and last 2,000 to 3,000 hours but cost $50 to $100 per bulb and require a ballast (a small electronic box) to operate. LED bulbs last 10,000 to 25,000 hours, cost $50 to $150 per bulb, and are becoming standard on newer vehicles.

Your owner's manual will state which type you have. If you've lost the manual, search your vehicle's year, make, and model plus "headlight bulb type" online, or call your car's dealership parts department—they can tell you in one call. Do not guess. Installing the wrong bulb type can damage your headlight housing, void your warranty, or fail to work at all.

How to replace a halogen bulb yourself

If your car has halogen bulbs and they're accessible from inside the engine bay, replacement is straightforward. Open your hood and locate the headlight assembly that's burned out. Behind the headlight lens, you'll see a plastic or rubber bulb socket. Grip the socket firmly and twist it counterclockwise—it should come free in one or two full rotations. Pull the socket straight out toward you.

The bulb sits inside the socket. Grip it gently and pull straight out. Do not touch the glass of the new bulb with your bare fingers—skin oils can cause the bulb to overheat and fail prematurely. If you've already touched it, wipe it with a clean, dry cloth. Insert the new bulb into the socket, push it in until it seats, then twist the socket clockwise back into the headlight assembly until it's snug. Turn on your headlights to confirm the new bulb works.

Repeat this process for the other headlight, even if it hasn't burned out yet. Mismatched brightness or color temperature between the two sides looks wrong and can affect your night vision.

When you need to remove the entire headlight assembly

Some vehicles require you to unbolt the headlight assembly itself to reach the bulb. This is common on older cars and some compact models. Open your hood and look for bolts or clips around the edges of the headlight housing. Your owner's manual will show you exactly where they are and what size socket or screwdriver you need.

Unbolt or unclip the assembly carefully—it's plastic and can crack. Once loose, gently pull the assembly forward and out. You'll see a wiring harness plugged into the back. Squeeze or press the release tab on the connector and pull it free. Now you can access the bulb socket from behind the assembly. Twist it counterclockwise, remove the old bulb, install the new one, and reverse the process: plug the harness back in, slide the assembly back into place, and bolt it down.

Take a photo of the bolt locations before you start, so you remember which bolts go where. Headlight assemblies are expensive to replace if you lose or cross-thread a bolt.

LED and HID bulb replacements

LED and HID bulbs are physically similar to halogen bulbs but require different handling. HID bulbs come with a ballast—a small electronic module that regulates power to the bulb. If you're replacing an HID bulb, the ballast usually stays in place; you only swap the bulb itself. LED bulbs sometimes require a resistor or decoder module to prevent error messages on your dashboard, especially on newer vehicles with onboard diagnostics.

If you're upgrading from halogen to LED or HID, the installation is more complex. You'll need to install the ballast or resistor module, which may require splicing wires or finding a safe mounting location under the hood. Many people choose to have a shop do this work rather than risk damaging the wiring harness. The labor cost is usually $50 to $150 per side, plus the cost of the bulb and any additional hardware.

Sealed headlight units and when to see a shop

Some modern vehicles, particularly luxury brands and newer models, have sealed headlight units that cannot be serviced at home. The entire assembly is glued or welded together, and there's no access to the bulb from inside the engine bay. If your manual says your headlights are sealed, or if you open the hood and see no visible bulb socket or assembly bolts, you need a shop visit.

A dealership or independent shop will remove the entire headlight assembly, replace the bulb or the entire unit if necessary, and reinstall it. This typically costs $200 to $500 per side, depending on whether they're replacing just the bulb or the whole assembly. It's expensive, but it's the only safe way to do it without damaging the vehicle.

Dim headlights that aren't burned out

If both headlights are dim but neither bulb is burned out, the problem isn't the bulb. Common causes are a corroded connector where the wiring harness plugs into the headlight assembly, a failing alternator that isn't charging the battery fully, or a battery that's old and not holding charge. A corroded connector is the easiest fix: unplug the connector, clean both the male and female ends with a wire brush or fine sandpaper, and plug it back in. If that doesn't work, have a shop test your alternator and battery.

Dim headlights are a safety issue—they reduce your visibility at night and make it harder for other drivers to see you. Don't ignore this. If cleaning the connector doesn't fix it, get the electrical system tested within a week or two.

Frequently Asked Questions

Can I replace just one headlight, or do I have to replace both?

Technically you can replace just one, but you shouldn't. A new bulb is brighter and whiter than an old one, so the two sides will look mismatched. This affects your night vision and looks unprofessional. Replace both at the same time to keep them even.

What's the difference between a 9005 and a 9006 bulb?

These are standard bulb sizes used across many vehicles. A 9005 is typically the high-beam bulb; a 9006 is typically the low-beam. Your manual will tell you which one you need. Installing the wrong size won't fit the socket.

Do I need to calibrate or aim the headlights after replacing a bulb?

If you're only replacing the bulb and not removing the headlight assembly, no. If you removed the entire assembly, the aim should still be correct when you reinstall it in the same position. If the headlights seem misaligned after replacement, have a shop check the aim—it's a quick adjustment.

Why do some headlight bulbs cost $20 and others cost $100?

Halogen bulbs are cheap because the technology is old and straightforward. LED and HID bulbs are more complex, last much longer, and produce brighter light, so they cost more. Luxury vehicles often use proprietary bulbs that are more expensive than standard sizes.

Is it safe to drive with one headlight out?

It's legal in most places for a short time, but it's not safe. You have reduced visibility on that side, and other drivers may not see you clearly. Replace the bulb within a day or two.