Toyota Supra Brake Light Switch Guide (1986-1998)
Solve brake light, cruise control, and shifting problems on your Mk3 or Mk4 Supra with the right replacement switch.
- A faulty brake light switch is a critical safety issue; replace it immediately if your brake lights are not working.
- Symptoms include brake lights staying on (check for a broken pedal stopper first), lights not working, cruise control failure, and being unable to shift from Park.
- Replacement is simple and can be done in under an hour with basic tools, but requires adjustment for proper function.
- Before ordering, verify if your Supra needs a 2-pin or 4-pin switch by checking the original part.
Symptoms of a Failing Brake Light Switch
A bad brake light switch on a Supra can be a major safety issue. The symptoms are usually straightforward. You might find that your brake lights don't turn on at all, or they stay on constantly, even when the car is off. This can drain your battery overnight. A common point of failure, especially on older cars like the Mk3 Supra, is a small plastic or rubber stopper on the pedal assembly that presses the switch's plunger. When this stopper breaks and falls apart, the switch thinks the pedal is always pressed, leaving the lights on.
Other symptoms can be more confusing. On automatic models, a bad switch can prevent you from shifting out of Park. Your cruise control might stop working because it isn't receiving the correct signal from the switch. In some cases, an ABS warning light may also appear 🎬 Watch this video to learn more about common switch symptoms. on your dashboard.
Is it the Switch or Something Else?
Before replacing the switch, always check the simple things first. Make sure your brake light bulbs aren't burned out and check the brake light fuse. On Mk3 and Mk4 Supras, a faulty tail lamp failure sensor (a small box in the trunk) can also cause brake light issues, though this often relates to a false warning light on the dash due to bad ground connections at the tail light sockets.
🎬 Learn how to repair a faulty lamp failure warning light.Choosing an Aftermarket Brake Light Switch
For a part this critical to safety, quality matters. While an OEM switch from Toyota is always a reliable choice, several aftermarket brands offer quality replacements that meet or exceed original specifications. Here’s a look at the available options:
- Beck Arnley: Often considered a top-tier aftermarket brand, Beck Arnley specializes in parts for foreign nameplates and aims to match OE form, fit, and function. They often source parts from the same manufacturers that supply Toyota, making them a very solid choice.
- Standard Ignition (SMP): A well-known and generally respected aftermarket manufacturer. Their parts are typically a reliable, standard replacement option for daily drivers.
- Facet: An Italian brand that produces a wide range of electronic components. They state their parts are made to OE equivalent specifications and are a common option in Europe and North America. Reviews are generally positive, indicating they are a decent replacement part.
- Rostra Powertrain: Rostra is a major manufacturer of automotive accessories, including universal cruise control systems and various sensors. Their replacement parts are designed as direct-fit OE replacements.
Pro Tip: Check Your Pins
Brake light switches for this generation of Supra can come with either 2 or 4 pins (terminals) depending on the vehicle's options (like cruise control). Before ordering, it's a good idea to look at your existing switch to confirm the number of pins to ensure you get the correct part.
Aftermarket & OEM Brake Light Switch Cost (1986-1998 Toyota Supra)
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket | $21.59 - $55.79 |
| New OEM | $31.00 - $85.00 |
| Shop Labor | $70 - $103 |
Frequently Asked Questions
Is it difficult to replace a Supra brake light switch?
No, it's a relatively easy job. The switch is located on a bracket above the brake pedal. You'll need to work in the driver's footwell, which can be cramped. The process involves disconnecting the electrical connector, loosening a locknut, and unscrewing the switch. Installation is the reverse, but the new switch must be adjusted correctly so the lights activate and deactivate at the right pedal position. The entire job usually takes less than an hour.
My brake lights are stuck on. Is it the switch?
Most likely, yes. This is a classic symptom. Often, it's not the switch itself but a small plastic or rubber stopper on the brake pedal arm that has disintegrated. When this stopper is gone, the switch's plunger is no longer held in, and the car thinks the brakes are always on. You can often find pieces of the old stopper on your floor mat. 🎬 See why your brake lights might stay on constantly. Check this before buying a new switch.
Are there any recalls for the brake light switch on my Supra?
No specific recalls were found for the 1986-1998 Toyota Supra concerning the brake light switch. While Toyota has issued recalls for this part on other models due to contamination during manufacturing, the A70 and A80 Supra were not included in those campaigns.
Will a new brake light switch fix my cruise control?
It might. The brake light switch is responsible for deactivating the cruise control when you press the brake pedal. If the switch is faulty and sending a constant "brake on" signal (or no signal at all), the cruise control system will not engage. If your cruise control stopped working at the same time you noticed brake light issues, a new switch is very likely the solution.
Helpful Videos
Technical Specifications
OEM Part Numbers: 84340-32050 84340-22100 84340-32110 84340-30050 84340-22110
Located on the brake pedal bracket. Typically features a 2-pin or 4-pin electrical connector. Operates via a mechanical plunger that is depressed by the brake pedal arm when at rest.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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