Toyota 86 Brake Lights Not Working But Others Are Fine - What Are The Causes

By Nick Marchenko, PhD

Experiencing brake light failure on your Toyota 86 can be troubling, especially if you're unsure where to start with troubleshooting. This DIY guide compiles insights from various discussions and offers a step-by-step approach to diagnosing and fixing brake light issues. Whether it's a fuse problem, a burnt-out bulb, or an issue with the brake light switch, this guide will help you tackle the problem efficiently.

Tools and Materials Needed

• Flashlight
• Mirror (optional for better visibility)
• Fuse puller or needle-nose pliers
• Replacement fuses (7.5 amp)
• Replacement brake light bulbs
• Basic hand tools (for accessing the brake light switch)

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Troubleshooting Steps

Step 1: Check the Fuses

1. Locate the Fuse Box: The fuse box is under the dash. Use your vehicle's manual to find the exact location and refer to page 279 for a detailed diagram.
2. Identify and Inspect the Fuse: Look for the 7.5 amp fuse in position number 6. Use a flashlight and possibly a mirror to get a good view.
3. Use a Fuse Puller: Remove the fuse using a fuse puller found in the large fuse box under the hood.
4. Inspect the Fuse: Check if the fuse is blown. A blown fuse will have a broken wire inside.
5. Replace if Necessary: If the fuse is blown, replace it with a new 7.5 amp fuse.

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Step 2: Inspect the Brake Light Bulbs

1. Access the Brake Light Assembly: Open the trunk or access the brake light assembly from the exterior, depending on your Toyota 86 model.
2. Remove the Bulb: Twist the bulb holder counterclockwise and pull it out.
3. Check the Bulb: Look for signs of damage or blackening inside the bulb.
4. Replace the Bulb: If the bulb is faulty, replace it with a new one.

Ensure you use the correct bulb type as specified in our bulb size chart:

• 2021;
• 2020;
• 2019;
• 2018;
• 2017;

Step 3: Test the Brake Light Switch

1. Locate the Brake Light Switch: It is usually found near the top of the brake pedal.
2. Check for Continuity: Using a multimeter, check for continuity between the two terminals of the switch when the brake pedal is pressed.
3. Inspect for Physical Damage: Look for any signs of damage or wear on the switch.
4. Replace if Defective: If the switch is not functioning correctly when tested, replace it.

Step 4: Inspect for Condensation and Wiring Issues

1. Check for Condensation: Condensation inside the tail light assembly can cause issues. Remove any moisture and check for damaged seals.
2. Examine Wiring: Look for any signs of wear, tear, or disconnection in the wiring that leads to the brake lights.

Final Checks

After going through the troubleshooting steps, perform a final check to ensure everything works as expected:

• Turn on your vehicle and press the brake pedal.
• Ask someone to confirm that the brake lights illuminate properly.
• Check that the lights increase in brightness when the brakes are applied and return to normal when released.

Conclusion

Fixing brake light issues on your Toyota 86 can be straightforward with the right approach and tools. By systematically checking the fuses, bulbs, and brake light switch, you can identify and solve common problems. Regular maintenance and visual inspections of the brake light system can prevent future failures and ensure your vehicle remains safe on the road.

Nick Marchenko, PhD

Industrial Engineer & Automotive Content Specialist

Nick writes in-depth guides on car clubs, engine specs, vehicle ownership, and modifications, combining engineering knowledge with automotive passion.

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