My '92 Civic vx brake lights do not come on all the time when the brake is applied. In connection, when the lights do not work, the horn does not work either. I understand that these two systems share the same circuit due to the fact that they utilize the same fuse in the underhood fuse box, but on occasion, but not very often, they work just fine. (I can test if my brake lights are working by tapping my horn.) My only guess is there's a wiring issue, but I don't know where it would be to always affect *both* systems at the same time. Also, when the horn and lights are not working, pressing the horn button results in the relay on the underdash fusebox to click, so I know that particular circuit is not open. If anyone has any advice or if you've heard of a similar problem, please let me know. Thanks.

 

Can you nail down which relay is making the sound to change it out?

 

I realize this is an old post but this is the same problem I am having with my 93 Civic DX. Mine is not intermittent though, I have no horn or brake lights. I checked the fuse, brake switch, and the actual bulbs themselves and all appear good. I have not checked the horn switch, but I don't believe the two are interconnected once they leave the fusebox. I have power at both sides of the fuse. Anyone run into this problem before?