2001 Honda Civic - no power to brake light socket

civic
honda

#1

We have a 2001 Honda Civic 4 door sedan. The right brake light stopped working. The bulb is good but there is no power to the socket.
With the bulb removed, the turn signal indicator flashes fast, but normal with the bulb inserted. This sounds to me like a clue! Anybody got an idea?


#2

It’s pretty common to get a bad connection due to corrosion of the contact points where the metal part of the bulb contacts the metal part of the socket. the corrosion might be a thin and nearly invisible oxide layer. try this first: use a pencil eraser to clean the bulb contact points, and the same or just scrape the socket contact points with something. sandpaper might work. I had that exact problem with the high center stop light bulb on my Corolla just a few weeks ago. the next most common problem is that the fixture’s ground wire has detached from its chassis grounding point. third most common is a blown fuse.


#3

Since posting this, I discovered that the four way flashers which use the same bulbs work fine, so I know the bulbs, wiring, sockets and grounds are good. Thanks


#4

The problem might be with the multi-function switch.

https://www.rockauto.com/en/moreinfo.php?pk=937779&cc=1373217&jsn=379

The brake light circuit passes thru this switch.

Tester


#5

Thank you, I have ordered the part and will post back when installed and hopefully working!


#6

If it’s just one socket without power, that would be an open circuit somewhere downstream of the multifunction switch. At least that’s how I interpret the circuit diagram for my 1999 Civic.


#7

According to the circuit diagram I’m looking at the current path to light the brake light bulb starts at the battery, then through fuse 7 (under hood), then through a under dash fuse relay box, to the brake pedal switch, then through some sort of under-dash relay/multi-plex circuit, then to the light bulb socket, and from there to chassis ground. Either the underdash fuse/relay box or the multi-plex box must contain the flasher relay. Unfortunately the engineer who drew the diagram didn’t show that explicitly for some reason. I don’t see any direct involvement w/the multi-function switch, except perhaps for the ground path. In any event the OP can probably jumper the ground directly, for testing purposes, if it isn’t evident by visual inspection the ground for the socket is already wired to the chassis. (The ground wire is solid black from what I see.)

Note that the brake light bulb has two filaments, so the fact that it lights up in certain situations doesn’t imply both filaments are good.

The brake light switch powers all three brake bulbs via white/black wires to each fixture. If two of the bulbs work, seems like there must be a problem between where the single path becomes 3 paths and the non-working bulb or its ground. It may be necessary to trace it out point to point starting at the brake light switch.


#8

Well, this is embarrassing! The car belongs to my son in law and he removed the bulb, matched it at the store and replaced it. Of course it didn’t work because he removed the four way flasher bulb. Thus the confusion on my part because I did not check it myself. I should know better, sorry for wasting everyone’s time.


#9

Most who are here often have gone too far down the wrong path, at least a time or two, in our auto repair efforts. I’ve learned that in troubleshooting a light bulb mystery, if a new bulb isn’t the answer, go to the owners manual and make sure of the bulb part # for that location.

Thanks for getting back here with the outcome. There was power to the socket all along, correct?


#10

Thanks for the update OP. Glad you got your brake lights working again.