My brake lights ain`t working

[Jools]

Hi all,

yesterday I noticed that neither brake lights are working. I checked the bulbs, but they seem ok. I also checked the regular fuses, but could not find any problem. I checked the connections near the sockets and cleaned them, but no result.

Any of you have an idea what this can be?

Jools

[murcod]

From memory the wiring loom for the rear lights runs under the carpet/ door opening trim on the left hand side of the vehicle. There is at least one plug under the carpet near the side edge of the passenger seat (assuming RHD vehicle here.) It then runs up through the rear LHS interior trim panel (behind where the rear speaker is mounted) and goes out though the floor at the rear LHS (from memory). I think there are some plugs under the floor externally as well.

Hmmmmm, I just had a think about it and you probably don't have the brake lights in the bumper bar like we do here in Aus? Some of the above will still be applicable hopefully.

The other thing to do is check the wiring around your brake light switch at the top of the brake pedal. If the wires are soldered on check they haven't come loose. Also try shorting out the switch terminals with a screw driver or something metal- that will bypass the switch to check if it's working or not.

[Jools]

David,

The lights are mounted in the bumper of the car, and it`s a LHD. I`ll check what you described and let you know the results.

Thanks so far.


Jools

[*BESTY*]

Buy yourself a cheapo multimeter and remove the globe....insert multimeter and see if its getting current (before you go ripping your door trims off !!

[Jools]

The globe gets current; it`s a combined 5W/21W globe, and the normal lighting works.

Just came to my mind that the brake lights did stop stop functioning simultaniously; first he right one quit, later the left.

[SimplyPV]

jools.... i had the exact same problem..... cept mine was the fuse. mine is lhd so not sure if this will be much use to you. i know that the running lights and turn lights fuses are in the standard fuse box. but it took me 2 hours to find the brake fuse! turns out it is right behind the brake pedal, stuffed into the bottom of the dash, very hard to get to, very hard to see. atleast it was in my experience. its a small box holding one fuse. since 1 light went out, then the other, i'm betting that your wires are getting a bad connection at the fuse box itself or fell out all together... also a possiblity of the fuse gone bad.... look around, see what you can find. keep us updated

[murcod]

Buy yourself a cheapo multimeter and remove the globe....insert multimeter and see if its getting current (before you go ripping your door trims off !!

I didn't mean to start ripping the panelling apart!

I was giving a heads up on where the looms run in case Jools doesn't have any luck and needs to go chasing connectors for corrosion etc.

[Area54]

The fuse would be okay, as you mentioned they did not fail together.

The bulbs have two filaments, one for brake and the other for taillights. the brake filament will be broken, you did not mention that you inspected the bulbs visually for filament damage.

Check the contacts for voltage as Ferozius mentioned, be careful of course not to short it out, you'll have to replace the fuse also then. If you don't own a multimeter, bulbs are pretty cheap...

[ShinyDiscoBalls]

That happened to me.... replaced both globes even though the old ones were fine and suddenly started working?????

Don't ask me what it was as they have been fine since.....

[yoda]

I whould say your lamps have done there 2000h. All lamps have a gas charge to retard the oxidation of the filiment. In the case of a car they normaly last about 2000h wich amount to a fair bit of stoping but dont forget once you drive at night and stop you use twice as much of the gas.
Buy new lamps and it will work fine.

[Jools]

Problem solved; credits go to Ferocious and Yoda!!

I first checked the brake fuse which SimplyPV described, but the thing turned out to be fine. As a last attempt I replaced both lamps, and suddenly darkness was conquered!!!

God, I feel dumb

But thanks fellas for all your advice.

[Area54]

Yep no worries, glad I got a mention...seeing as I was the first to mention you had problematic bulbs...

[Jools]

Sorry for stepping on your toes mate. Indeed you were the first with this suggestion.

[yoda]

I dont want the spotlight I just wanted to explain why a light stops working but the filiment is intac.

Ferocious is the man of the moment.

[lay80n]

once or twice at work i have had cars with globes that are intermitantly inoperative. have noticed on some that the fillament is broken but as it bounces round each bit makes contact with the other, completing the circut. dont see it too often , but maybe possibility when globes were not working then working and rest of circut is ok. usually though with a visual inspection the fillament can be seen to be damaged

[ShinyDiscoBalls]

Yep no worries, glad I got a mention...seeing as I was the first to mention you had problematic bulbs...

Hooray for Area54!!!!



Glad you got it sorted.

[yoda]

hail to the great 54

[Area54]

Oh, stop it, will you, your PM's and thank-yous of flowers are just too much. and my wife is getting jealous from offers from the lovely chicks...

[Jools]

Last comment before we should drop it; both filaments are fine! No damage at all...

All you see is that the inside of the glass is slighty coloured. Whatever ...

Lesson learned; first change bulbs, then try other options.

[Area54]

Back on track here, the discolouration on the inside of the bulbs is the vapourised tungsten from the filament bonded to the glass. Over time the tungsten 'burns' off the filament and the gas can no longer support a saturated amount of tungsten, so it vulcanises to the glass.