Adrian has been a diesel and auto mechanic for 7 years. He is also a veteran and the recipient of the Driver and Mechanic badge.
So, Your Brake Lights Are Broken
If you own a Honda (or an Acura) and find that your brake lights won't turn off even after removing the key, I'm happy to tell you that the solution is usually simple and cheap.
When you press down on the brake pedal, a brake pedal switch bumper on the top of the pedal assembly moves away from a plunger, activating the brake light switch. It is highly likely that a deteriorated or missing brake pedal switch bumper is the cause of your problem.
Diagnosing the Issue
The first step is to examine the floorboard beneath the pedals. There, you will almost certainly find crumbles of blue or yellowish rubber that is broken and dry.
These crumbs are a clue that your brake pedal switch bumper has succumbed to old age and caused your brake light problem.
When age and heat get the best of the bumper, it cracks and falls out of place. With no bumper in place, the brake light switch has nothing to keep it in place, so the circuit remains open.
To confirm this is the problem, slide your hand up along the brake pedal until you find an empty hole.
The part you will need will depend on your diagnosis.
If your brake pedal switch bumper is broken or missing, you will need a replacement brake pedal switch bumper.
If the bumper is intact, you may need a brake light switch.
How to Fix Your Brake Lights
Now that you've diagnosed the issue, fixing the problem yourself is simple.
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Go to an auto parts store or Honda dealership and ask for a brake pedal switch bumper. These should cost less than $5. You may have to buy a rubber bumper assortment, which will also do the job. The assortment will come with a number of bumpers, but the one that you will need will be flanged with a flat, round top (pictured below).
To begin replacing the brake pedal switch bumper, you will need to:
- Start your car. In order to replace the part, you need to create a vacuum in the braking system, which is only possible with the car running.
- Press the brake pedal with one hand.
- With the other hand, slide the brake light switch bumper up the brake pedal, feeling around for the hole where it will go. The flat portion of the switch bumper should be facing the rear of the vehicle.
- When you get the flanged part of the switch bumper into the hole, push it hard so it can't easily come out. Sometimes universal bumpers are a little too large to fit, so clipping a little rubber off of the flange can help.
- When the bumper is in place, release the brake and the plunger will press against the new part. Your brake lights should now turn off!
If the Bumper is Intact, Try Replacing the Switch
A broken brake light switch bumper is the likeliest cause of Honda or Acura brake light issues, but sometimes a broken brake light switch is the culprit.
If, when you feel the brake pedal, you find that the rubber brake light switch bumper is in place, press the pedal and manually push the plunger on the brake light switch.
Have an assistant check for proper operation of the brake lights.
Sometimes the plungers stick and require a bit of lubrication, but other times the spring inside the brake light switch assembly can break. Most brake light switches are only $10 to $30 and are fairly easy to replace. To do this, you will need to:
- Unplug the switch.
- Loosen the adjustment nut with an 18-mm wrench.
- Once the adjustment nut has been loosened from the mounting plate, the threaded brake light switch can be unscrewed by hand and removed.
- Screw-in a new brake light switch.
- Tighten the adjustment nut. Your brake lights should now turn off!
Fixing "Stuck" Brake Lights Video Tutorial
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.