Brake Lights

Hello everyone! I have a problem and i really need some help. Any help would be wonderful. OK here it goes… I have a 1990 Honda Accord and my brake lights dotn work. When i turn my head lights on the back lights come on. I have checked the bulbs and the are fine, my brake light switch it not the problem (I already tried to change that) and I just can’t figure it out. Here is whats happening. I thought it was my brake light switch because I can shift out of park when the car is off without useing my shift lock release. But I changed it yeserday and that did not help. My horn and stop lights are on the same fuse and i changed that but it did not help. The crazy thing is my horn does not work unless my lights are on. All i can think of is its must be a wiring problem or some sort of relay. I jsut don’t know! Help me please!

thank you,


Perhaps it’s the wire to the brake light switch. This is one of those where someone may have to take a voltmeter with pin probes and follow the path back to where the voltage is. It isn’t a complicated path, it doesn’t go through the ignition switch or any computers (your brake lights always work despite the status of your ignition switch), but that may be the only way to find the problem.

I suspect the horn vs. lights problem is a different problem. That one will probably end up in your steering column. The two circuits, the one for the brake lights and the one for the taillights, are enabled through different pathways even though they both end up in the same two-filament lightbulb.

I suggest you purchase a test light probe from a auto parts store if you don’t have one. That way you can test to see where power is actually getting to and figure out which direction from that point in the circuit you need look for the problem. Check the brake switch and see if power is present there on one of the connections. If it isn’t then the trouble is towards the fuse. If there is power there and it switches ok the trouble is towards the lights.

The horn problem is most likely due to a grounding problem. Check the connection between the negative battery terminal and the chassis. Also check dash area grounding. If you want, you can make a long ground jumper by tieing one end of a wire to the negative battery terminal and then move the other end around to suspected bad ground points and see if touching the wire to the point makes a difference.