Disconnecting the Electrical Wiring
There are many variations of brake light switches, so please refer to your repair manual or do a quick online search for the exact location of your brake light switch. Once you have located the brake light switch, you will need to disconnect the electrical wiring.
1. Locate the electrical connector. It is usually a small, black or white plastic connector that is plugged into the brake light switch.
2. Disconnect the electrical connector. To do this, you will need to squeeze the sides of the connector and pull it straight off of the brake light switch.
3. Identify the wires. There are typically two wires that are connected to the brake light switch. One wire is the power wire, and the other wire is the ground wire.
4. Disconnect the wires. Use a pair of wire cutters to cut the wires about 6 inches from the brake light switch. Be sure to cap the ends of the wires with electrical tape to prevent them from shorting out.
| Wire Color | Description |
|---|---|
| Red or black | Power wire |
| Black or white | Ground wire |
Removing the Old Switch
Locate the Switch
Find the brake light switch, typically mounted on the brake pedal arm. It’s usually a small, cylindrical or rectangular switch with electrical connectors attached.
Disconnect the Electrical Connectors
Locate the electrical connectors plugged into the switch and unplug them by pressing the release buttons or tabs. Ensure no wires are damaged during removal.
Remove the Mounting Bolt
Most brake light switches are secured by a single mounting bolt or screw. Identify the bolt, usually located on the side of the switch, and use an appropriate hex or Torx wrench to remove it.
Extract the Switch
Once the bolt is removed, carefully pull the switch out of its mounting bracket. Avoid twisting or bending the switch, as it may damage the components or wiring.
Check for Damage
Before installing the new switch, inspect the removed switch for physical damage or wear, such as cracks, melted contacts, or frayed wires. These issues may indicate underlying brake system problems that need to be addressed.
Installing the New Switch
Once you’ve removed the old switch, it’s time to install the new one. Here’s what you’ll need to do:
- Locate the mounting bracket for the brake light switch. It’s usually located on the firewall or near the brake pedal.
- Align the new switch with the mounting bracket and push it into place. You may need to use a wrench to tighten the nut that holds the switch in place.
- Connect the electrical connector to the new switch. Make sure the connector is firmly seated.
- Depress the brake pedal several times to make sure the new switch is working properly. The brake lights should come on when you press the pedal and go off when you release it.
- If the brake lights are not working properly, check the following:
Possible Cause Solution The switch is not properly installed. Remove the switch and reinstall it, making sure it is firmly seated in the mounting bracket. The electrical connector is not properly connected. Disconnect the connector and reconnect it, making sure it is firmly seated. The switch is defective. Replace the switch with a new one.
Troubleshooting Common Issues
1. Check the Brake Light Switch
Start by visually inspecting the brake light switch. Look for any obvious damage or corrosion. If you find any damage, you will need to replace the switch.
2. Test the Brake Light Switch
You can test the brake light switch using a multimeter. Set the multimeter to the ohms setting. Disconnect the electrical connector from the brake light switch. Touch the probes of the multimeter to the terminals of the switch. The multimeter should read 0 ohms when the brake pedal is depressed and infinity when the brake pedal is released.
3. Check the Brake Pedal Linkage
The brake pedal linkage can become loose or damaged over time. This can cause the brake light switch to not work properly. Inspect the brake pedal linkage for any signs of damage or looseness. If you find any damage, you will need to repair or replace the brake pedal linkage.
4. Check the Bulbs
If the brake light switch is working properly, but the brake lights are still not working, check the bulbs. The bulbs may have burned out. To replace the bulbs, remove the brake light assembly from the vehicle. Remove the old bulbs and install the new bulbs. Make sure to install the bulbs in the correct orientation.
5. Check the Wiring
The wiring to the brake light switch can become damaged or corroded over time. This can cause the brake lights to not work properly. Inspect the wiring for any signs of damage or corrosion. If you find any damage, you will need to repair or replace the wiring.
6. Check the Fuses
If the brake light switch, bulbs, and wiring are all working properly, but the brake lights are still not working, check the fuses. The fuses may have blown. To check the fuses, locate the fuse box in your vehicle. Remove the fuse box cover and locate the fuse for the brake lights. If the fuse is blown, replace it with a new fuse.
7. Check the Brake Light Relay
Some vehicles have a brake light relay. The brake light relay is a small electrical component that controls the brake lights. If the brake light relay fails, the brake lights will not work. To check the brake light relay, locate the relay in your vehicle. Remove the relay and inspect it for any signs of damage or corrosion. If you find any damage, you will need to replace the brake light relay.
8. Check the Brake Fluid Level
The brake fluid level can affect the brake light switch. If the brake fluid level is low, the brake light switch may not be able to engage. Check the brake fluid level in your vehicle. If the brake fluid level is low, add brake fluid until the reservoir is at the correct level. **Brake fluid level can be checked by looking at the fluid level in the see-through brake fluid reservoir that is usually located under the hood of the vehicle near the master cylinder. The correct level of brake fluid is usually indicated by markings on the reservoir. Brake fluid level is low if the fluid is below the indicated markers.**
Tips for Easier Replacement
1. Gather Tools
Before you start, ensure you have the necessary tools: a socket set, wrenches, needle-nose pliers, and a flashlight.
2. Disconnect Battery
Safety first! Disconnect the vehicle’s battery to prevent electrical shocks.
3. Locate the Switch
The brake light switch is typically located under the dashboard, near the brake pedal.
4. Remove Bolts/Screws
Use the socket set or wrenches to remove the bolts or screws securing the switch in place.
5. Pull Out and Disconnect
Carefully pull out the old switch and disconnect the electrical connector by pressing the release tab.
6. Install New Switch
Plug in the new switch’s electrical connector and push it into place until it securely clicks.
7. Tighten Bolts/Screws
Use the socket set or wrenches to tighten the bolts or screws that hold the new switch in place.
8. Reconnect Battery
Reconnect the vehicle’s battery to restore power and test the brake lights.
9. Test Brake Lights
Press the brake pedal to ensure the brake lights activate properly.
10. Additional Tips for Easier Replacement
| Tips | Additional Details |
|---|---|
| Use a flashlight | Illuminate the area under the dashboard for better visibility. |
| Use needle-nose pliers | Easily remove small retaining clips or springs. |
| Apply electrical grease | Prevent corrosion and improve electrical connections. |
| Check other bulbs | Inspect tail light and turn signal bulbs while accessing the brake light switch area. |
