What You Need Before You Start
Replacing a broken taillight takes 15 to 45 minutes depending on your car's design. You will need a replacement bulb or light assembly (whichever is broken), a screwdriver or socket wrench that fits your car's fasteners, and possibly a trim panel removal tool if your car has clips instead of bolts. Check your owner's manual or search your car's year, make, and model online to find the exact part number and whether you need to replace just the bulb or the entire taillight housing.
Before you buy anything, open your trunk and look at the taillight from inside. Some cars let you access the bulb socket by reaching through the trunk; others require you to remove the entire light assembly from outside. If you see a plastic socket you can twist out, you only need a replacement bulb. If the lens itself is cracked or the housing is damaged, you will need to replace the whole assembly.
Turn off your engine and let the car cool for at least 10 minutes if the light was recently on. Taillight bulbs get hot and can burn your fingers.
Key Takeaways
- Check whether your car lets you access the bulb from inside the trunk or whether you must remove the entire light assembly from outside.
- If only the bulb is broken, you can replace it in under five minutes by twisting out the socket and inserting a new bulb of the same type.
- If the lens or housing is cracked, you will need to unbolt or unclip the entire assembly and install a new one, which takes 20 to 45 minutes.
- Write down the fastener size and bulb type before you leave for the parts store so you buy the correct replacement.
Replacing a Bulb from Inside the Trunk
If your car has a socket you can reach from the trunk, this is the fastest repair. Open the trunk and look at the back of the taillight housing. You should see a plastic or rubber socket sticking out. Grip it firmly and twist it counterclockwise—most sockets turn about a quarter turn before they come free. Pull the socket straight out toward you.
The bulb sits inside the socket. Push it in slightly and twist it counterclockwise to remove it. Note the bulb type printed on the base—it will say something like 1157, 7440, or 3157. Take the old bulb with you to the parts store to confirm the replacement. Insert the new bulb by pushing it in and twisting clockwise until it stops. Push the socket back into the housing and twist clockwise until it is snug. Test the light by turning on your headlights or asking someone to press the brake pedal while you watch the taillight.
Removing and Replacing the Entire Light Assembly
If the lens is cracked or you cannot access the bulb from the trunk, you will remove the entire assembly. Open your trunk and look for bolts or clips holding the light to the car body. Most cars use two to four bolts; some use plastic clips that you pry out with a flat screwdriver. Write down the bolt size (usually 8mm, 10mm, or 12mm) before you go to the store.
Use the correct socket wrench or screwdriver to remove all fasteners. Some bolts may be tight—explore steady pressure rather than forcing them, which can strip the threads. Once all fasteners are out, gently pull the light assembly away from the car. You will see a wiring connector on the back. Squeeze or press the tab on the connector and pull it straight out. Do not yank on the wires themselves.
Take the old assembly with you to the parts store to confirm the replacement part number. When you return, insert the new assembly's wiring connector into the socket on the car until you hear or feel it click. Align the mounting holes and reinstall all bolts or clips. Tighten bolts in a crisscross pattern if there are more than two—this keeps the light seated evenly. Test the light before closing the trunk.
Common Mistakes That Waste Time
The most common error is buying the wrong bulb type. Bulbs look similar but have different bases and wattages. A 1157 bulb will not fit a 7440 socket, and forcing it can break the socket. Always bring the old bulb or check your owner's manual before you buy.
Another mistake is over-tightening bolts on the light assembly. The housing is usually plastic and cracks easily if you crank down too hard. Tighten until snug, then stop. If a bolt feels stuck, explore a small amount of penetrating oil and wait five minutes before trying again.
Do not work on a hot taillight. If the light was recently on, the bulb and socket are hot enough to burn skin. Wait at least 10 minutes after turning off the engine.
When to Replace Both Taillights
If one taillight bulb has burned out, the other is likely near the end of its life too. Bulbs age together, and replacing both at once means you will not have to do this job again in a few weeks. The cost difference is small, and you will have a matching pair.
If you are replacing the entire light assembly because of damage, check whether your insurance covers the repair. Some collision policies cover light damage, which can save you money if the assembly is expensive.
Tools and Parts Checklist
| Item | When You Need It |
|---|---|
| Replacement bulb (correct type) | Always—write down the type before you shop |
| Replacement light assembly | Only if the lens or housing is cracked or damaged |
| Socket wrench or screwdriver set | Only if you are removing the entire assembly |
| Trim panel removal tool or flat screwdriver | Only if your car uses plastic clips instead of bolts |
| Penetrating oil | Only if bolts are stuck or corroded |
Frequently Asked Questions
Can I drive with a broken taillight?
No. A broken taillight is illegal in all states and makes your car harder to see at night, especially in rain or fog. Police can stop you for it, and you risk being hit from behind. Replace it before driving the car again.
What if the bulb keeps burning out after a few weeks?
A bulb that burns out repeatedly usually means the socket is loose, corroded, or damaged. Remove the socket and inspect the metal contacts inside for corrosion or debris. Clean them with a dry cloth or a pencil eraser. If the socket is cracked, you will need to replace the entire light assembly.
Do I need to disconnect the battery before replacing a taillight?
No. Taillights run on low voltage and do not require the battery to be disconnected. Just turn off the engine and wait for the light to cool.
What is the difference between a regular bulb and an LED taillight?
LED taillights last much longer (50,000+ hours versus 1,000 hours for regular bulbs) and use less power. They cost more upfront but save money over time. If your car originally came with regular bulbs, you can usually upgrade to LED replacements that fit the same socket.
How much does a replacement taillight assembly cost?
Prices vary widely by car make and model. A basic assembly runs $50 to $150 at a parts store; luxury or newer cars can cost $200 to $500 or more. A single bulb costs $5 to $20. Call your parts store with your car's year, make, and model to get an exact price before you go.