Brake lights ..2001 Honda Civic

Notified by another motorist both my brake lights were out. Replaced both bulbs didn’t solve the problem. Also noticed my cruise control isn’t working so I checked the fuse but it’s okay too. Next thought is the brake light switch but oddly the third brake light ( on the spoiler) is functioning fine which makes me think the brake light switch isn’t the problem. Any one can steer me in the right direction.

You may have the brake light monitor located inside the driver side brake light housing that is supposed to light up the bar under your door ajar icon on the dash when ever a brake light burns out. Sometimes the monitor goes out and this is the condition you get.

You may also have a 4 pin brake light switch in which the center brake light is activated by a separate contact within the switch, so it could also be the brake light switch itself. You need to consult with someone who has either a service manual for that car with schematics or wiring diagrams or an account with AllData or similar service.

Since the middle light is working check to see if the emergency flashers are working okay. The brake light circuit usually runs through that switch. Also try cycling the switch a few times to see if that corrects the issue. There may be dirty contacts in that switch causing the problem.

Emergency flashers are working just fine. Perhaps I should remove the switch, clean the contacts and put it back in?

On the 2001 Civic DX Sedan the brake light switch appears to be operated by the brake pedal itself. That must be working, otherwise there’d be no lights at all. The power to light the brake lights goes from there on a white/black wire to all three brake lights, the two on the corners and the one on the spoiler. Since the spoiler light is working, there must either be a broken wire or loose connector somewhere in the line that powers the two corner lights. Has the car been in an accident or has work been done on it just before you noticed this problem? If so, you know where to look. The problem could be either in the white/black wire or the grounds. Are you able to measure the voltage at the bulb connector on both of the corner lights? That would be a good place to start. The way to tackle this scientifically is to secure the wiring diagrams for your car, then you can trace it from the stop light switch from one connector to the next until you find the break.

No accidents and no recent work to the car. The cruise control failing to function is what tipped to me off to a problem other then just abulb burnt out. So as it stands I’ve got working flashers, spoiler light working. no cruise control and no corner brake lights

Take a flashlight and have a good look in the brake pedal area, see if you notice anything unusual.

Brake light switch is a part of the Cruise Control System. So if the cruise is not working I would suspect the switch.

I checked a diagram for you car and it shows that the brake lights are separate from the other circuits. There is a splice connection to the middle light so the trouble is most likely at that splice point. By following the middle light wiring it should lead you to the splice connection.

I’m thinking I’ll start with the switch. The cruise control malfunctioning makes me think it’s the switch

The two things are very likely related to each other alright but I doubt there is a separate switch contact to turn on the middle brake light. The data I looked at shows a single switch contact and a splice in the line after the switch going to the other brake lights. Since the CC is not working it may mean that splice is under the dash.

I just thought of something here, duh. The CC doesn’t require power from the brake switch to work. Applying the brakes disables the CC. You stated the fuse for the CC was okay but have you verified that power is getting to that fuse? Another thing to check is the safety switch on the brake pedal if there is one. Sometimes that switch just requires an adjustment.

Are the lights that are not working actually mounted on the trunk lid? If so there could be a broken wire where the wiring transitions from the car body to the trunk lid. It happened on my old Camry.

Nope brake lights are on the corners. I’ve seen it mentioned there’s a wiring harness in the rear drivers side where all that wiring runs into the trunk and broken wires aren’t uncommon.

You may have the brake light monitor

I would also try to pick one of these up at a junk yard as this usually does not monitor the 3rd light and is a common denominator between both corner lights.

Update …problem solved. Believe it or not it was simply bad bulbs. The cruise control not working really threw me off but simply replacing both bulbs solved all the issues.

Always try the easy stuff first.