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Ford Mustang Brake Light Switch Guide: 1971-1993 Problems and Replacement

Fixing brake lights that are stuck on or won't light up on your classic Mustang.

4 minutes to read 1971-1993 Ford Mustang
Difficulty
1/5
Est. Time
0.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$50-$100
🚫 Do not drive — It is not safe to drive because other drivers will not be able to tell when you are slowing down, creating a high risk of a rear-end collision.
Key Takeaways
  • Symptoms of a bad switch include brake lights that don't work, stay on constantly, or being unable to shift out of park.
  • This is a critical safety repair that should be done immediately.
  • Replacement is simple and very DIY-friendly, typically taking less than 30 minutes with basic tools.
  • Quality aftermarket brands like Standard Ignition are a reliable and cost-effective choice for this part.
The brake light switch on a 1971-1993 Ford Mustang is a simple but critical safety part. It is a small, spring-loaded electrical switch mounted to the brake pedal support bracket. When you press the brake pedal, the pedal arm moves away from the switch's plunger. This allows the switch to complete an electrical circuit, sending power to your rear brake lights. When you release the pedal, it presses the plunger back in, breaking the circuit and turning the lights off. On models with an automatic transmission, it also sends a signal that allows the shifter to move out of Park.

Diagnosing a Bad Brake Light Switch

A failing brake light switch on your Mustang will cause obvious and unsafe problems. Because this part is used every time you drive, it's common for it to wear out. The plastic can become brittle and the internal spring can fail after decades of use. Look for these key symptoms:

  • Brake Lights Don't Work: The most common failure. The switch no longer completes the circuit when the pedal is pressed. Before replacing the switch, always check for blown fuses and bad bulbs first.
  • Brake Lights Stay On: The switch can fail in the 'on' position, or the plunger can get stuck. This will drain your battery and confuse drivers behind you. 🎬 Watch how to easily fix brake lights that stay on This can also be caused by a missing or worn-out plastic bumper on the pedal assembly that is supposed to press the switch when the pedal is at rest.
  • Can't Shift Out of Park: On automatic transmission models, the car requires a signal from the brake switch before it will allow the shifter to move out of the Park position. If the switch is bad, you may be stranded.
  • 🎬 See an easy fix if you can't shift out of park
Safety First: Driving with brake lights that don't work or are always on is a major safety hazard and can get you a ticket. This is a repair that should be done immediately.

Choosing the Right Aftermarket Switch: 1971-1993 Mustang

For a straightforward part like a brake light switch on a classic Mustang, you don't always need to pay extra for a dealership OEM part. The technology is simple, and quality aftermarket brands provide reliable replacements that meet or exceed original specifications.

Brand Options:

  • Standard Ignition (SMP): This is a well-known and widely available aftermarket brand. They offer direct-fit replacement switches for the 1971-1993 Mustang and are a trusted choice for everyday repairs.
  • Rostra Powertrain: While Rostra is a manufacturer of automotive switches, their catalog primarily focuses on components for newer or different vehicle makes. Finding a Rostra brake light switch specifically for this generation of Mustang is unlikely.

For this repair, a new switch from a reputable aftermarket brand like Standard Ignition is a perfectly good choice and offers excellent value.

Pro Tip: The 1979-1993 Fox Body Mustangs generally use the same switch (OEM part E9ZZ-13480-A). However, the 1971-1973 models may have different switches for manual versus power brakes. Always confirm the part fits your specific year and brake setup before ordering.

Cost of Replacing a Ford Mustang Brake Light Switch (1971-1993)

Item Estimated Cost
New Aftermarket Switch $16.58 - $26.40
New OEM Switch $17.00 - $36.00
Shop Labor $50 - $100
DIY Total $16.58 - $26.40
Shop Repair Total $67 - $126

Frequently Asked Questions

Is it hard to replace a Mustang brake light switch?

No, it is a very easy job for a DIY mechanic. The only challenge is the location. The switch is up under the dashboard, attached to the brake pedal assembly, so it can be an awkward spot to reach. The process involves unplugging the wire connector, removing a small retaining clip, and swapping the old switch for the new one. It typically takes less than 30 minutes.

🎬 Watch this quick Foxbody brake light switch replacement guide
Why are my brake lights stuck on?

This usually happens for one of two reasons. First, the switch itself has failed internally and is stuck in the 'on' position. Second, and very common, a small plastic bushing on the brake pedal arm that's meant to press the switch's plunger has broken or fallen off. Without this bushing, the switch is never pressed, and the lights stay on. Inspect the pedal arm for a small hole where a bushing should be.

Can I drive with a bad brake light switch?

No. If your brake lights don't work, other drivers won't know you are stopping, which is extremely dangerous. If your lights are stuck on, it can confuse other drivers and drain your battery. This is a critical safety issue that should be repaired immediately before driving the vehicle.

Did Ford ever recall the brake light switch for these years?

No specific recalls were found for the brake light switch on 1971-1993 Ford Mustangs. Recalls for brake light issues on Mustangs are for much newer models (2014-2015) and relate to a different part (a pedal bumper) failing.

How To: Foxbody Brake Light Switch
How To: Foxbody Brake Light Switch
BRAKE LIGHTS STAY ON, HOW TO FIX IT EASILY! MUST WATCH!
BRAKE LIGHTS STAY ON, HOW TO FIX IT EASILY! MUST WATCH!
Can't Shift Out Of Park-Easy Solution
Can't Shift Out Of Park-Easy Solution

Technical Specifications

OEM Part Numbers: E9ZZ-13480-A (Fits most 1979-1993 models) C9AZ13480C (Referenced for 1971-1973 models)

Mounts to brake pedal support. Activated by pedal arm movement. Typically has a 2-terminal electrical connector.

Wrenchy
Article researched & written by
Go-Parts' AI research assistant. Every article is backed by live web research, verified OEM data, and real technician knowledge — so you get accurate, up-to-date information you can trust.
Meet Wrenchy → Updated Jul 21, 2026

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.

Year Coverage
This article covers the Brake Light Switch for:
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