1967-1974 Mercury Cougar Brake Light Switch Diagnosis and Replacement
Keep your classic Cougar safe and legal by fixing common brake light switch problems.
- A bad brake light switch is a critical safety issue; replace it immediately if your brake lights don't work.
- Verify if you have power or manual brakes before ordering, as the switches are different and not interchangeable.
- The problem might be a loose wire, a bad circuit breaker, or the turn signal switch, not the brake light switch itself.
- Replacement is simple but requires working in an awkward position under the dashboard.
Is Your Cougar's Brake Light Switch Failing?
A faulty brake light switch is a serious safety issue. Because these switches were designed to handle the current for six tail light bulbs, they can wear out over time. Watch for these common signs of failure.
Symptoms of a Bad Brake Light Switch
- Brake Lights Don't Work: The most obvious and dangerous symptom is when your brake lights do not light up at all when you press the pedal. This can be caused by a switch that has failed internally.
- Brake Lights Stay On: If the switch shorts in the 'on' position, your brake lights will stay lit even when your foot is off the pedal. This can confuse other drivers and will drain your car's battery.
- Flickering or Intermittent Lights: The switch contacts can wear out, causing the brake lights to flicker or only work some of the time.
Check This First!
Before you replace the switch, check for simpler problems. Make sure the wiring connector is securely plugged into the switch under the dash. Also, check the shared circuit breaker for the brake lights and hazard lights; if your hazards don't work either, the circuit breaker could be the problem.
Choosing the Right Aftermarket Switch
Finding a new original Ford (OEM) brake light switch for a classic Cougar is nearly impossible. You will be buying a new aftermarket reproduction part. The two main brands you'll find are Standard Ignition and Rostra Powertrain, along with specialty reproduction brands like Scott Drake.
- Standard Ignition (Standard Motor Products): This is a widely available and generally trusted aftermarket brand. Their parts are often considered a reliable replacement for original components.
- Rostra Powertrain: Rostra makes many electrical parts, but they are less commonly discussed in classic Cougar forums for this specific switch.
Pro Tip: The most common mistake is ordering the wrong switch for your brake system. There are different switches for manual brakes and power brakes. Using the wrong one will lead to improper fitment and failure. Always verify the part number for your specific application.
Fitment Issues with Reproduction Parts
Be aware that some reproduction switches may have slight fitment issues. Forum members have reported needing to slightly modify the switch or having trouble with bushings. This is a common challenge when working with aftermarket parts for classic vehicles.
Brake Light Switch Cost for 1967-1974 Cougar
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket Switch | $12.66 - $41.13 |
| Shop Labor | $100 - $150 |
| New OEM (NOS) | $75+ (if found) |
Frequently Asked Questions
Where is the brake light switch located?
The brake light switch is mounted on the brake pedal support bracket, up under the driver's side dashboard. You will need to look above the brake pedal arm to see it.
Can I replace the brake light switch myself?
Yes, this is a DIY-friendly job. However, it requires working in a cramped, uncomfortable position under the dash. The job involves removing a retaining clip and pin, unplugging the old switch, and installing the new one. Some owners remove the driver's seat to get better access.
Is there a difference between switches for manual and power brakes?
Yes. The switches for manual and power brakes are different, often having springs with different stiffness. Installing the wrong part will cause it to fail or not work correctly. For example, part number C9ZZ-13480-A is often for manual brakes, while C9ZZ-13480-B is for power brakes. Always confirm the correct part for your car's setup.
My brake lights still don't work after replacing the switch. What now?
If a new switch doesn't solve the problem, the issue lies elsewhere in the electrical circuit. The power for the brake lights runs through the turn signal switch in the steering column, which is a known failure point. You could also have a bad ground, a break in the wire, or a faulty bulb socket.
Technical Specifications
OEM Part Numbers: C5AZ13480B C5AZ13480C C7ZZ13480B C9ZZ13480A C9ZZ13480B C9VY13480A
Mechanical plunger-style switch mounted on the brake pedal support. Two-prong electrical connector. Specific design varies between manual and power brake applications.
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.