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2000 Honda Civic SiR Brake Lights/Horn

Recently, a friend was riding his motorcycle behind me and he told me my brake lights were out. We met in a parking lot and looked under the hood for the fuse. It was a 15A fuse that shared the horn and brake light circuit, and it was blown. We replaced the fuse, then my friend sat in the driver’s seat while I stood behind the car; he stepped on the brake pedal and I could see the lights engage. He held the horn for several seconds and it worked fine. Problem solved? Nope.



My car uses keyless entry, so whenever I hit the key fob to unlock the car the brake lights flash. When the car is at idle, and the headlights are on, the brake lights are ALSO on. However, when driving the car, whether the headlights are on or off, the brake lights will not engage when the brake pedal is compressed. After surfing come Honda forums, I also evaluated the brake light bulbs for failure, but they were fine. I also checked the brake switch near the brake pedal, while my friend stood behind the car, and when I compressed the switch the brake lights worked fine. The consistent problem is this: When the car is parked, the horn and brake lights work flawlessly. When I’m driving the car, neither the horn nor the brake lights work. Further, the horn/brake light fuse blows consistently, but does not seem to affect the horn/ brake lights when the car is parked.



What is going on here?

CreativeRider, have you done any mods to the electrical system or audio system? Any accessory lighting? Aftermarket audio system?

I have taken out the stock stereo system and replaced it with component speakers in the front doors, 6x9s in the rear deck, and a sub and two amplifiers in the trunk. The stereo system does not interfere with any wiring pre-existent in the vehicle. I also have had a HID headlight conversion, as well as added aftermarket side-view mirrors with LED-integrated lights that illuminate when the parking/headlights are on. Additionally, the car is equipped with aftermarket illuminated gauges that monitor turbo boost, oil pressure, exhaust gas temperature, and water pressure. To handle the extra current draw of the stereo system, the upgraded lighting, and the gauges, I recently had a 160A alternator installed (Which is about double the amperage of the stock alternator).

That’s what I figured.

Sorry, but I can’t offer any help on this one. You’ve created an electrical abomination.

Sincere best.

“Additionally, the car is equipped with aftermarket illuminated gauges that monitor turbo boost, oil pressure, exhaust gas temperature, and water pressure.”

Geez, my '75 Civic CVCC didn’t even have a tach.