Changing a rear light takes 15 to 30 minutes and costs $5 to $25 for the bulb

A rear light that has burned out needs to be replaced before you drive again — it is a safety issue and a legal requirement. The process is straightforward: you remove the lens cover (or sometimes just the bulb socket), take out the old bulb, and install a new one. Most cars let you do this from inside the trunk without special tools, though the exact steps depend on your vehicle's design.

The hardest part is usually finding the right bulb type for your car, not the replacement itself. Your owner's manual lists the correct bulb number, or you can take your old bulb to an auto parts store and match it. Once you have the right bulb, the installation takes minutes.

Key Takeaways

  • Your owner's manual or the bulb itself will show you the bulb type number — bring this to an auto parts store if you are unsure what to buy.
  • Most rear light replacements happen from inside the trunk by twisting out the bulb socket or unbolting a lens cover.
  • Let the light cool for a few minutes after driving before you touch it, since the bulb and housing get hot.
  • Test the light before you close the trunk — have someone stand behind the car while you turn on the lights, or use a reflective surface to check.

Locate the burned-out light from inside the trunk

Open your trunk and look at the inside wall where the rear light housing sits. You will see either a plastic lens cover held on by bolts or screws, or a bulb socket that sticks out from the housing. The socket is usually a plastic cylinder with a rubber or plastic base. If you see bolts or screws around the edge of the lens, you will need to remove those first. If you see a socket, you can proceed directly to removing it.

Some cars have the light housing accessible from outside instead — if you cannot find it in the trunk, check whether there is a panel or cover on the rear bumper or quarter panel that you can remove. Your owner's manual will show you the exact location for your model.

Remove the bulb socket or lens cover

If your car has a bulb socket sticking out from the housing, grip it firmly and twist it counterclockwise. It should turn about a quarter turn before it comes free. Pull it straight out toward you. If your car has a lens cover held by bolts or screws, use the appropriate wrench or screwdriver to remove them — usually three to four fasteners — and set them aside in a small container so you do not lose them.

Once the socket is out or the lens is off, you will see the bulb itself. It may be held in by a wire clip, a plastic collar, or straightforward pushed into a socket. If it has a clip, gently pry the clip away from the bulb. If it has a collar, twist it counterclockwise. If it is just pushed in, pull it straight out.

Install the new bulb

Before you touch the new bulb with your bare hands, check whether it has a plastic base or a metal base. If it has a metal base with two prongs (called a bayonet fitting), align the prongs with the slots in the socket and push straight in, then twist clockwise until it stops. If it has a plastic base that pushes straight in, straightforward insert it into the socket until it clicks or seats fully.

If the old bulb had a wire clip, slide the clip back over the new bulb. If it had a plastic collar, twist the collar clockwise until it is snug. Do not force anything — the bulb should seat smoothly without pressure.

Reattach the socket or lens cover

If you removed a bulb socket, push it straight back into the housing and twist it clockwise until it stops. You should feel a slight resistance as it seats. If you removed a lens cover, line up the bolt holes and reinstall the bolts or screws. Tighten them firmly but do not overtighten — you want them snug enough that the cover does not rattle, but not so tight that you crack the plastic.

Close the trunk and move to the next step to test the light before you drive.

Test the light before driving

Turn on your headlights or brake lights (depending on which rear light you replaced) and have someone stand behind the car to confirm the light is working. If no one is available, back up close to a garage door, wall, or other reflective surface and look for the light's reflection. If the light does not come on, turn off the car, open the trunk again, and check that the bulb socket is fully seated and twisted all the way in. If it is, the bulb itself may be defective — try a different new bulb.

If the light works, you are done. If you replaced a brake light, test it by having someone press the brake pedal while you watch. If you replaced a turn signal, turn the steering wheel and confirm the light blinks.

What to do if the light housing is cracked or leaking

If you open the trunk and see moisture inside the light housing, or if the lens cover is cracked, replacing just the bulb will not solve the problem. Water inside the housing will corrode the socket and cause new bulbs to fail quickly. In this case, you need to replace the entire light housing, not just the bulb. This is a larger job that may require removing the bumper or rear panel, so it is worth having a mechanic handle it.

A cracked lens also means the light is not waterproof anymore. Driving with a cracked lens is legal in most places, but the light will fail sooner because water will get inside. If the crack is small and does not affect the light's brightness, you can drive it until you have time to replace the housing. If the crack is large or the light is dim, replace the housing before your next long drive.

Frequently Asked Questions

Can I replace a rear light bulb without opening the trunk?

Some cars have access panels on the rear bumper or inside the wheel well that let you reach the socket without opening the trunk. Check your owner's manual or look for a removable panel behind the bumper. Most sedans and SUVs require trunk access, but some trucks and vans do not.

What if I cannot twist the bulb socket out?

The socket may be stuck from corrosion or age. Let the light cool for 10 minutes if you just drove, then try again with a firmer grip. If it still will not budge, wrap a rubber band around the socket for extra grip, or gently tap the base with a rubber mallet to loosen it. Do not force it hard enough to crack the plastic housing.

Is there a difference between brake light and turn signal bulbs?

Yes — they are different bulb types with different brightness levels and sometimes different bases. Your owner's manual lists which bulb goes in which socket. If you put a turn signal bulb in a brake light socket, the brake light will be too dim. If you put a brake light bulb in a turn signal socket, the turn signal will be too bright and may confuse other drivers.

Do I need to disconnect the battery before changing a rear light?

No. Rear light bulbs operate on low voltage and pose no shock risk. You do not need to disconnect the battery or turn off the car. Just make sure the lights are off and the bulb has cooled before you touch it.

What if the new bulb burns out after a few days?

A bulb that fails when ready may be defective, or there may be a deeper electrical problem. Take the bulb back to the auto parts store where you bought it and ask for a replacement — most stores will swap a defective bulb for free. If the replacement also fails within a few days, have a mechanic check the wiring and socket for corrosion or a short circuit.