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Mercury Sable Brake Light Switch Guide: 1986-1990

Understanding how to diagnose and replace the brake light switch in your first-generation Mercury Sable.

3 minutes to read 1986-1990 Mercury Sable
Difficulty
1/5
Est. Time
0.25 hrs
DIY Doable?
✅ Yes
Shop Labor
$50-$100
🚫 Do not drive — Driving without functional brake lights is extremely dangerous and illegal; the vehicle should be repaired immediately.
Key Takeaways
  • A faulty brake light switch is a critical safety issue; do not drive if your brake lights are not working.
  • Symptoms include brake lights not working, staying on, or cruise control failure.
  • Always check the brake light fuse before assuming the switch has failed.
  • Replacement is simple for DIYers and located on the brake pedal arm.
The brake light switch on your 1986-1990 Mercury Sable is a simple but critical safety component. It is a small sensor located on the brake pedal arm under your dashboard. When you press the brake pedal, the switch activates, turning on your brake lights to alert other drivers. On models equipped with cruise control, this switch also serves to disengage the system as soon as you tap the brakes. A functioning switch is essential for both road safety and proper operation of your vehicle's features.

Symptoms of a Failing Brake Light Switch

A bad brake light switch on your Sable can cause several distinct and potentially dangerous problems. 🎬 Watch this video to learn more about common switch failure signs. The most obvious sign is if your brake lights do not turn on when you press the pedal, which is a major safety hazard. Conversely, the switch can fail in the 'on' position, causing the brake lights to stay on constantly, 🎬 See why your brake lights might be staying on all night. which can drain your battery and confuse other drivers. You might also notice that your cruise control no longer works, as a faulty switch can prevent it from activating. In some cases, a failing switch can also cause the brake lights to flicker intermittently.

Immediate Safety Concern

If your brake lights are not working, your vehicle is not safe to drive. The risk of a rear-end collision is extremely high. You should diagnose and repair the issue before driving.

Choosing the Right Aftermarket Switch

For a first-generation Mercury Sable, the brake light switch is a straightforward mechanical part. While an OEM (Original Equipment Manufacturer) part is always an option, high-quality aftermarket brands offer reliable performance at a lower cost. Here's a breakdown of the available brands:

  • Motorcraft: This is Ford's official parts brand, making it the direct OE equivalent. Choosing Motorcraft ensures you are getting the same quality and fit as the part your Sable was built with. It is often the most expensive option but guarantees compatibility.
  • Standard Ignition (SMP): Standard is a well-regarded aftermarket manufacturer known for producing quality electronic components that meet or exceed OE specifications. For a part like a brake light switch, Standard is a dependable choice that often provides a long service life.
  • Rostra Powertrain: Rostra has a long history of manufacturing automotive electronics. While often associated with transmission components and cruise control systems, their switches are generally considered a reliable and cost-effective alternative to OEM parts.

OEM vs. Aftermarket Quality

For a simple mechanical switch on a vehicle from this era, the quality difference between a top-tier aftermarket brand like Standard and an OEM Motorcraft part is often minimal. The most critical factor is ensuring the part is listed as a direct fit for your 1986-1990 Sable to ensure proper installation and function.

Typical Costs for Brake Light Switch Replacement

Part Type Estimated Cost
New Aftermarket Part $11 - $29
New OEM (Motorcraft) Part $17 - $40
Shop Labor $50 - $100

Frequently Asked Questions

Can I replace the brake light switch myself?

Yes, this is a very DIY-friendly repair. The switch is located on the brake pedal assembly under the dashboard and is typically easy to access. 🎬 Follow this easy guide to fix your non-working brake lights. It usually involves disconnecting the electrical connector and then twisting or unclipping the switch from its bracket. No special tools are typically required.

Are there any recalls for the 1986-1990 Sable brake light switch?

No, extensive searches of the NHTSA database show recalls for brake light switches on newer (2000-2004) Mercury Sables, but there are no active or past recalls for this specific part on the 1986-1990 models. The issues on newer models were related to different designs and materials.

What happens if I don't replace a bad brake light switch?

Continuing to drive with a faulty switch is dangerous. If your brake lights don't work, other drivers won't know you are slowing or stopping, which can easily cause an accident. If they are stuck on, your battery will drain, and you could be left stranded.

Could a blown fuse be the problem instead of the switch?

Absolutely. Before replacing the switch, always check the fuse for the brake light circuit first. A simple blown fuse can cause the exact same symptoms as a failed switch and is a much easier and cheaper fix. If a new fuse blows immediately, it indicates a short circuit in the wiring that needs to be investigated.

SYMPTOMS OF A BAD BRAKE LIGHT SWITCH
SYMPTOMS OF A BAD BRAKE LIGHT SWITCH
SYMPTOMS OF A BAD BRAKE LIGHT SWITCH (REAR BRAKE LIGHT STAYS ON)
SYMPTOMS OF A BAD BRAKE LIGHT SWITCH (REAR BRAKE LIGHT STAYS ON)
Symptoms of a Bad Brake Light Switch You Shouldn’t Ignore
Symptoms of a Bad Brake Light Switch You Shouldn’t Ignore
Brake Light Won't Work - Easy Fix!
Brake Light Won't Work - Easy Fix!

Technical Specifications

OEM Part Numbers: E73Z-13480-A E1EB13480BA E73B 13480 AA

The brake light switch for this generation is a 2-terminal, mechanical plunger-style switch that mounts to the brake pedal bracket.

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 Mar 31, 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:
  • Mercury Sable: 19861987198819891990
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