A non-functioning license plate light can be a minor inconvenience or a major headache, depending on where you live. In some states, it’s illegal to drive with a burned-out license plate light and you could face a fine. In addition, a non-functioning light can make it difficult for police to identify your vehicle, especially at night. So, if you find yourself with a burned-out license plate light, it’s important to fix it as soon as possible. The good news is that it’s a relatively simple and inexpensive repair that you can do yourself with a few basic tools.
First, you’ll need to identify the type of license plate light you have. There are two main types: incandescent bulbs and LED bulbs. Incandescent bulbs are the traditional type of light bulb that uses a filament to produce light. LED bulbs are more energy-efficient and last longer than incandescent bulbs. Once you know the type of light bulb you have, you can purchase a replacement at your local auto parts store. The next step is to remove the old light bulb. To do this, simply twist the bulb counterclockwise until it comes loose. Be careful not to drop the bulb, as it can break easily.
Identifying the Malfunction
1. Inspect the License Plate Light Assembly
Start by visually examining the license plate light assembly for any visible damage or corrosion. Check for loose connections, broken wires, or damaged sockets. If you notice any loose connections, try tightening them. If any wires are broken, you may have to repair or replace them. Additionally, if the sockets are damaged, you may need to replace the entire assembly.
Here’s a table summarizing the common issues and their potential causes:
| Issue | Potential Cause |
|---|---|
| Broken wires | Wear and tear, accidental damage |
| Damaged sockets | Corrosion, heat |
| Loose connections | Vibration, improper installation |
| Corrosion | Moisture, road salts |
If you’re unable to identify any obvious damage or loose connections, proceed to the next step to diagnose the issue further.
Assessing the Bulb and Socket
Once you’ve identified the location of the license plate light and disassembled the assembly, it’s time to inspect the bulb and socket. Here’s what you need to check:
1. Bulb Filament:
Examine the bulb filament. If it’s broken or burnt out, it’s the likely cause of the malfunctioning light.
2. Bulb Socket and Contacts:
Carefully inspect the bulb socket and contacts. Look for any signs of corrosion, damage, or loose connections. If there’s corrosion, clean it gently with a cotton swab and rubbing alcohol.
Check the bulb’s contacts for debris or dirt. Clean any obstructions using a small brush or compressed air.
Contacts Inspection Table
| Observation | Action |
|---|---|
| Loose Contacts | Tighten them with a small screwdriver |
| Bent or Damaged Contacts | Replace the socket or bulb |
| Corrosion or Dirt | Clean with rubbing alcohol or compressed air |
Replacing a Faulty Bulb
Troubleshooting a license plate light typically involves replacing the faulty bulb. To do this safely, park your vehicle on a level surface, engage the parking brake, and turn off the engine. Locate the light assembly, which is usually situated on the rear bumper or trunk lid. Using a screwdriver or trim removal tool, carefully detach the light assembly from the vehicle.
Once the light assembly is removed, inspect the bulb socket for any signs of damage or corrosion. If the socket appears damaged, it may need to be replaced as well. The bulb can be removed from the socket by gently pulling it straight out.
| Bulb Type | Size |
|---|---|
| Incandescent | 168 or 194 |
| LED | 194 or 3157 |
When selecting a replacement bulb, it’s crucial to choose the correct type and size for your vehicle. The most common bulb types for license plate lights are incandescent and LED. Incandescent bulbs typically have a smaller base and are available in sizes 168 or 194. LED bulbs, on the other hand, have a larger base and are available in sizes 194 or 3157. Refer to your vehicle’s owner’s manual to determine the correct bulb type and size.
Once you have replaced the faulty bulb, reinstall the light assembly back onto the vehicle. Ensure that the assembly is securely fastened to prevent moisture and dirt from entering the bulb socket. Switch on the license plate light to verify if the issue has been resolved.
Inspecting the Socket and Wiring
If the bulb is intact, the next step is to check the socket and wiring. Use a flashlight to inspect the socket for any corrosion, debris, or damage. If the socket appears damaged, it may need to be replaced.
Checking the Fuse and Wiring Continuity
If the socket is intact, use a multimeter to check the fuse and wiring continuity. The multimeter should be set to the continuity setting. Touch one probe to the fuse terminal and the other probe to a ground point, such as the chassis or the negative terminal of the battery. If the multimeter shows continuity, the fuse is good. Repeat the process for the wiring, touching one probe to the socket and the other probe to the fuse terminal or a ground point. If the multimeter does not show continuity, there is a break in the wiring that needs to be repaired.
Cleaning the Socket and Connectors
If the socket is dirty or corroded, it may need to be cleaned. Use a wire brush or sandpaper to remove any corrosion or debris from the socket and the connectors. After cleaning, apply a small amount of dielectric grease to the socket and connectors to help prevent future corrosion.
| Issue | Potential Causes |
|---|---|
| No power to the socket | Fuse blown, damaged wiring, or faulty socket |
| Intermittent light | Loose connections, damaged wiring, or faulty bulb |
| Dim light | Weak bulb, dirty socket, or low voltage |
| Flickering light | Loose bulb, damaged wiring, or faulty socket |
Testing for Power at the Socket
Step 1: Verify the Socket Connection
Inspect the license plate light socket for any loose or disconnected wires. If so, reconnect them securely. Ensure that the socket is firmly plugged into the vehicle’s electrical system.
Step 2: Use a Multimeter to Measure Voltage
Set a multimeter to DC voltage measurement mode and touch the positive probe to the socket’s positive terminal and the negative probe to the negative terminal. A reading of 12-14 volts indicates power at the socket.
Step 3: Check for Continuity
Use the multimeter to test for continuity between the socket’s positive and negative terminals. A reading of 0 ohms or near 0 ohms indicates good electrical conduction.
Step 4: Check the Ground Circuit
Disconnect the socket from the vehicle’s electrical system. Touch the multimeter’s positive probe to the socket’s negative terminal and the negative probe to a metal surface on the vehicle’s frame. A reading of 0 ohms or near 0 ohms signifies a sound grounding connection.
Step 5: Troubleshooting
If no power is detected at the socket, the issue may lie in the wiring, fuse box, or other electrical components.
| Possible Cause | Troubleshooting Steps |
|---|---|
| Blown fuse | Check the vehicle’s fuse box and replace any blown fuses related to the license plate lights. |
| Damaged wiring | Inspect the wiring harness for breaks or loose connections. Repair or replace damaged wiring as necessary. |
| Faulty relay | Locate the relay responsible for the license plate lights and replace it if suspected to be defective. |
| Electrical system problem | Consult a qualified electrician or mechanic to diagnose and repair any underlying electrical issues. |
Troubleshooting Wiring Issues
Check the wiring harness connected to the lamp assembly. Look for loose or damaged connections, frayed wires, or corrosion.
Verify the ground wire connection. The ground wire should be securely attached to a metal surface on the vehicle’s frame or body.
Test the voltage at the lamp assembly using a voltmeter. The voltage should be present when the lights are turned on.
Check the continuity of the wiring from the lamp assembly to the light switch. Use a multimeter to ensure that the electrical circuit is complete.
Inspect the light switch for proper operation. Make sure the switch is clean and free of damage.
Replace any damaged or faulty wiring as needed. Ensure all connections are secure and properly insulated.
If the issue persists, it may be necessary to trace the wiring harness further along the vehicle’s electrical system to identify the root cause of the problem.
| Check | Possible Issue |
|---|---|
| Ground wire connection | Corrosion or loose connection |
| Continuity of wiring | Damaged or frayed wires |
| Voltage at lamp assembly | Open circuit or faulty wiring harness |
| Light switch operation | Contaminated or worn-out switch |
| Replacement of wiring | Correct gauge and type of wire used |
| Further tracing of wiring harness | Electrical system malfunction elsewhere |
Replacing the Socket
If the socket itself is faulty, it must be replaced. Here’s a step-by-step guide:
1. Remove the Lens and Housing
Gently pry off the license plate light lens using a flathead screwdriver or a similar tool. Once the lens is removed, locate the screws holding the housing in place and remove them.
2. Disconnect the Wiring Harness
Locate the wiring harness connected to the socket and disconnect it by pressing down on the release tab.
3. Unscrew the Socket
Find the screws securing the socket to the housing and carefully unscrew them. Remove the faulty socket from the housing.
4. Clean the Contact Points
Inspect the contact points on the housing and socket for any corrosion or dirt. Use a fine-grit sandpaper or a wire brush to gently clean the surfaces.
5. Install the New Socket
Insert the new socket into the housing and align it correctly. Secure it with the screws you removed earlier.
6. Reconnect the Wiring Harness
Reconnect the wiring harness to the socket by pressing down on the release tab until it clicks into place.
7. Assemble the Housing and Lens
Position the housing onto the license plate and secure it with the screws. Carefully replace the lens and ensure it fits snugly. Check that all the components are properly assembled.
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Materials Needed |
Tools Needed |
|---|---|
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Cleaning Corrosion
Corrosion can build up over time on the terminals of the license plate light and prevent it from working. To clean the corrosion, you will need:
- A screwdriver
- A wire brush
- A cotton swab
- Rubbing alcohol
Step 1: Remove the license plate light. Use the screwdriver to remove the screws that hold the license plate light in place. Once the screws are removed, you can pull the light out of its socket.
Step 2: Clean the terminals. Use the wire brush to clean the terminals on the back of the license plate light. Be sure to get into all of the nooks and crannies. Once the terminals are clean, wipe them down with a cotton swab dipped in rubbing alcohol. This will help to remove any remaining dirt or debris.
Step 3: Adjust the license plate light shield.
The license plate light shield is a small metal piece that sits behind the license plate light. It helps to direct the light onto the license plate. If the shield is bent or damaged, it can cause the light to shine in the wrong direction or not shine at all. Use a pair of pliers to adjust the shield so that it is straight.
Step 4: Reinstall the license plate light. Insert the license plate light back into its socket and tighten the screws. Make sure that the light is securely in place before turning it on.
Step 5: Test the license plate light. Turn on the license plate light and make sure that it is working properly. If the light is not working, check to make sure that the terminals are clean and that the shield is adjusted correctly.
Step 6: Replace the license plate light if necessary.
If you have tried all of the above steps and the license plate light is still not working, it may be necessary to replace the light. You can purchase a new license plate light at most auto parts stores. Replace the license plate light according to the manufacturer’s instructions.
Reassembling the Components
Reassembling the components of the license plate light is relatively straightforward. Here’s a detailed guide to help you with the process:
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Initial Steps
Before you begin, gather all the necessary tools and parts. Ensure you have a new license plate light bulb, a screwdriver, and a pair of pliers.
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Replacing the Bulb
Locate the license plate light assembly and remove the old bulb by turning it counterclockwise. Insert the new bulb and turn it clockwise to secure it.
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Reattaching the Lens
Align the license plate light lens with the assembly and gently press it into place until it snaps securely. Use the screwdriver to tighten the screws that hold the lens in place.
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Reconnecting the Wiring
Reconnect the wiring harness to the license plate light assembly. Ensure the wires are properly aligned and securely fastened.
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Testing the Light
Turn on the headlights or taillights to test the license plate light. If it’s not functioning, check the connections and make sure the bulb is properly seated.
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Additional Tips
If you encounter any difficulties, refer to the vehicle’s owner’s manual for specific instructions.
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Lubricating the Screws
Apply a small amount of lubricant to the screws to prevent them from seizing in the future.
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Checking the Wiring Harness
Inspect the wiring harness for any damage or corrosion. If necessary, replace the harness to ensure proper functionality.
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Using a Voltage Tester
To ensure the electrical system is working correctly, use a voltage tester to check the power supply to the license plate light. This will help identify any electrical issues.
| Tools and Materials | Purpose |
|---|---|
| Screwdriver | Tighten and loosen screws |
| Pliers | Remove and insert light bulb |
| Replacement bulb | Replace burned-out bulb |
| Lubricant | Prevent screws from seizing |
| Voltage tester | Check electrical system functionality |
Ensuring Proper Illumination
1. Check the Light Bulbs
The most common cause of a non-functioning license plate light is a burnt-out light bulb. Replace the bulb with a new one of the correct wattage and type.
2. Inspect the Socket
Ensure the light bulb socket is clean and free of rust or corrosion. If necessary, clean the socket with a wire brush or electrical cleaner.
3. Examine the Wiring
Check the wires connecting the light to the vehicle’s electrical system for any breaks or loose connections. Repair or replace any damaged wiring.
4. Test the Fuse
Locate the fuse that powers the license plate light and check if it’s blown. Replace it if necessary.
5. Examine the Switch
If the light bulb, socket, wires, and fuse are in good condition, the problem may lie with the switch that turns on the light. Test the switch with a multimeter.
6. Repair the Circuit
If the switch is not functioning properly, inspect the electrical circuit for any open circuits or shorts. Repair any identified issues.
7. Inspect the Grounding
Check the ground connection for the license plate light. Ensure it’s clean and securely attached to the vehicle’s frame.
8. Check for Obstructions
Examine the license plate light housing for any obstructions, such as dirt or debris, that may be blocking the light.
9. Ensure Clean Lens
Clean the license plate light lens to remove any dirt or grime that could reduce its effectiveness.
10. Consult Owner’s Manual
Refer to your vehicle’s owner’s manual for specific troubleshooting instructions and to identify the correct fuse and light bulb type.
| Common Troubleshooting Steps |
|---|
| Check Light Bulbs |
| Inspect Socket |
| Examine Wiring |
| Test Fuse |
| Examine Switch |
| Repair Circuit |
| Inspect Grounding |
| Check for Obstructions |
| Ensure Clean Lens |
| Consult Owner’s Manual |
How To Fix License Plate Light
Many states require your vehicle to have a properly functioning license plate light. Not only does this light help other drivers see your plate at night, but it can also help you avoid getting pulled over by the police.
If your license plate light is out, there are a few things you can do to fix it. First, check the bulb. If the bulb is burned out, you will need to replace it. You can find replacement bulbs at most auto parts stores.
If the bulb is not burned out, the problem may be with the wiring. Check the wires for any loose connections or damage. If you find any loose connections, tighten them. If you find any damaged wires, you will need to replace them.
Once you have checked the bulb and the wiring, try turning on the license plate light. If it still does not work, you may need to replace the entire light assembly.
