Replace the brake light switch located on the brake pedal assembly to restore brake light and shift interlock function.

Warnings

Tools required

Parts

• Brake light switch × 1 — Motorcraft SW-7125 or equivalent

Preparation

1. Park vehicle on level ground and engage parking brake firmly
2. Turn ignition to OFF position and remove key completely
3. Open driver's door and leave it open for access and interior lighting
4. Ensure you have adequate lighting to see under the dashboard above the brake pedal
5. Allow at least 30 minutes for any heated interior components to cool if vehicle was recently driven
6. Position yourself comfortably to access the area above the brake pedal - you may need to lie on your back with legs outside the vehicle

Procedure

1. 1

   Access the brake pedal area
   Remove the driver's side lower dashboard panel if necessary for better access. On most 2011-2014 F-150 models, you can access the brake light switch without full panel removal, but removing the panel makes the job significantly easier. If removing, locate the retaining clips or fasteners along the bottom edge of the panel below the steering column and carefully pry or unscrew them. Set the panel aside in a safe location.
2. 2

   Locate the brake light switch
   Using your flashlight, look above the brake pedal arm near where it mounts to the brake pedal bracket. The brake light switch is a small plastic component with an electrical connector, mounted on a bracket with the plunger portion contacting a pad on the brake pedal arm. The switch should be positioned so the plunger is depressed when the brake pedal is at rest (not pressed) and releases when the pedal is pressed.
3. 3

   Disconnect the electrical connector
   Locate the electrical connector on the brake light switch body. Press the locking tab on the connector (usually on the side or top) and pull the connector straight off the switch. You may need to wiggle it gently while pressing the tab. Do not pull on the wires themselves. If the connector is difficult to see, use your fingers to feel for the locking tab.
   ⚠The connector locking tab is plastic and can break if forced. Apply firm but controlled pressure only.
4. 4

   Remove the brake light switch
   The switch is typically held in place by a twist-lock mechanism or a sliding clip. For twist-lock type: rotate the switch body approximately 30-45 degrees counterclockwise (when viewed from the driver's seat) until it releases from the bracket, then pull it straight out. For clip type: press the locking tabs on either side of the switch body and pull straight out from the bracket. Note the orientation and position of the old switch before complete removal.
5. 5

   Inspect the mounting bracket and pedal contact area
   Examine the bracket where the switch mounts for any cracks or damage. Check the rubber pad or contact point on the brake pedal arm where the switch plunger makes contact. If this pad is missing or severely worn, it should be replaced as it affects proper switch operation. Clean any dirt or debris from the mounting area with a clean cloth.
6. 6

   Prepare the new brake light switch
   Remove the new switch from its packaging. Most replacement switches come with the plunger in a shipping position (fully extended or with a retaining clip). If present, remove any shipping clips or locks according to the instructions included with the new switch. Do NOT press the plunger in manually before installation as this can damage the self-adjusting mechanism on some switch designs.
7. 7

   Install the new brake light switch
   Position the new switch aligned with the mounting bracket holes or slots, ensuring the plunger will contact the brake pedal pad correctly. For twist-lock type: insert the switch into the bracket and rotate clockwise 30-45 degrees until it locks into place with an audible click. For clip type: push the switch straight into the bracket until the locking tabs engage. Ensure the switch is fully seated and cannot be pulled out without releasing the locking mechanism.
   ⚠Incorrect installation angle or position will cause the brake lights to malfunction. The plunger MUST contact the pedal pad when the pedal is at rest and release when the pedal is pressed, not the reverse.
8. 8

   Reconnect the electrical connector
   Push the electrical connector firmly onto the new switch until you hear or feel a distinct click indicating the locking tab has engaged. Gently tug on the connector (not the wires) to verify it is securely locked in place. The connector should not pull off without pressing the release tab.
9. 9

   Perform initial function test
   Without starting the engine, turn the ignition to the ON or RUN position (not ACC). Press and release the brake pedal several times while observing the brake lights. Have an assistant watch the rear brake lights, use a mirror, or back up to a wall/garage door to see the reflection. Brake lights should illuminate immediately when the pedal is pressed even slightly (within the first 1/4 inch of travel) and turn off completely when the pedal is released.
10. 10

    Test the shift interlock function
    With the ignition in the ON position and your foot OFF the brake pedal, attempt to move the shifter out of Park - it should be locked and immovable. Now press the brake pedal and the shifter should release and allow you to move it to other gear positions. Return to Park, release the brake, and verify the shifter locks again. This confirms the shift interlock circuit is functioning properly.
    ⚠️If the shifter moves out of Park WITHOUT pressing the brake pedal, the switch is incorrectly installed or defective. Do NOT drive the vehicle. Shut off the ignition and repeat the installation procedure or seek professional assistance immediately.
11. 11

    Reinstall lower dashboard panel
    If you removed the lower dashboard panel, align it with the mounting points and press or secure it back into place. Ensure all clips or fasteners are fully engaged and the panel is flush with the surrounding dashboard. Verify the panel does not interfere with brake pedal operation by pressing the pedal fully to the floor.

Reassembly

1. Ensure the electrical connector is fully locked onto the switch and cannot be pulled off without pressing the release tab
2. Verify the lower dashboard panel is properly secured and does not rattle or interfere with pedal operation
3. Confirm no tools or parts were left in the footwell area

Verification

• Turn ignition to ON position and verify brake lights illuminate when pedal is pressed and turn off completely when released - test multiple times
• Check that brake lights activate with very light pedal pressure (within first 1/4 inch of travel)
• Verify the shift interlock prevents shifting out of Park unless brake pedal is depressed
• Confirm the cruise control deactivates when brake pedal is pressed (if equipped)
• Test with engine running to ensure no warning lights appear on the instrument cluster related to brake system
• Have a second person verify all three brake lights function properly (two rear lights and center high-mount stop lamp)
• Perform a test drive in a safe area and verify brake lights function normally during actual braking
• If the vehicle has adaptive cruise control or collision warning systems, verify these systems still function properly as they may rely on the brake light switch signal

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