94 Civic Bizarre Electrical Problem (brake lights+instruments)

I have a 1994 Civic with a weird electrical problem. An electrical engineer friend gave it a once-over and said it was time to consult the WWWeb. What better than to consult the puzzle solvers here?!

My brake lights stopped working a few days ago (which a police officer was kind enough to point out). The third light still works properly, however, so the brake pedal switch is working. The bulbs are good (checked with multimeter). All the under-dash fuses are good; however after I checked them I realized that the turn signals were no longer working, front or rear. And then I realized that all the gauges had stopped working, though the dash lights still work.

The emergency flashers still work, as do the running lights, so the harness to the rear of the car must be okay. All the fuses in the underhood fuse box are fine.

The day following the beginning of this problem the car overheated, and I thought that perhaps the fan had become part of the problem, but there was a pinhole leak so that might have been a coincidence - or the pinhole leak (which I’d repaired before with stopleak) might have sprung again because of overpressure caused by the fan not working. I’m not sure if the fan is going on or not; I certainly have not heard or seen it go on since.

I am mystified as to what and whether the common cause of all this could be. I would certainly be grateful for any ideas. Thanks!

Half the bizarre problem is solved: Last night I studied a diagram in a manual I downloaded from hondahookup.com and discovered that I had pulled the gauges fuse from a blank slot and replaced it in the wrong blank slot - the diagram on the fusebox cover shows three contiguous blank spaces, but the diagram in the manual indicates that one of those is the spot for the gauges. So I have my gauges, turn signal and radiator fan back, and a lesson about how to create more problems than I started with.

So now I’m left with a mystery as to where the common fault in the brake circuit might be. I didn’t mention before that the fuse for the brakes/horn is good and the horn works, so it has to be downstream from the fuse and obviously from the brake pedal, as the third light works.


Verify you have power at the lights when pushing the brake, if so I would start looking for a bad ground somewhere. if not look for a connector or wires that may have been knocked loose by things in the trunk.

I’ll do that, thanks.

You stated that the emergency flashers worked along with the turn signals so the grounding to the lights should be ok. The brake light circuit may run through the emergency flasher circuit and the turn signal multi-function switch if you have one. I suspect the trouble is between those two areas. Cycling the switches a few times may make things work again. The flasher unit could be the trouble also.

Hi, Cougar,

Sorry to take so long to reply and thank you. An electrical engineer friend examined the system and thought there was an open in the rear part of the harness, downstream of the middle light’s branch junction, b/c he’d checked the junction and sockets at the brake lights and found them dead. Perhaps a ground came back somehow, but when I rechecked them today, in preparation for running a bypass, I found the junction and sockets live. I reexamined the bulb and saw it was good and it registered continuity on my multimeter, but when I put in a new bulb just to check it anyway it worked. So, eyes rolling, I checked the other side and found the other bulb had a blown filament (though we’d looked at it before). It’s weird that two bulbs would fail simultaneously, and in a way that was deceptive, but who am I to complain about the gremlins of electricity - or even my own stupidity, if that was at work also?! :~))

Anyway, thank you very much!


You’re welcome for the help Dan and glad you got things back to working. I would guess the trouble was with the emergency flasher switch as the brake light circuit most likely passes through it. The middle light bypasses it though so it works. The contacts of the switch get dirty and so the outside brake lights fail to work.