(T) Brake lights constantly on!

Hi, my headlights went a few days ago and with little time at the moment ive used my sidelights although today the car has developed another fault! the brake lights including the 3rd brake light, remains on all of the time with the ignition on and the headlights on, however if you take the headlights off the 3rd brake light is still constantly on although the brake lights go off, also the brake lights do not change condition from being on or off when the brake pedal is pressed/depressed. Does anyone know what this could be? Many Thanks Alex

My breaklights kept on staying on on my 3 door Abarth Stilo. Caused all sorts of problems with my ASR sensor. Found the problem to be the break pedal drops slightly onto the breaklight switch...Fitted a return spring to the pedal and it solved everything (Remove trim under dash next to pedals) Takes about half an hour to do but gives you a backache. Hope this helps

Paul, the brake pedal returns up to the brake light switch when you release it so all you need to do is adjust the brake light switch with a pair of long nosed pliers then release the pedal carefully and it will reset itself.

Just pull out the black centre plunger which you can do in situ.
Somewhere along the line you have pushed up the brake pedal beyond normal and reset the brake switch too high. Easily done as you just need to trap your foot under the brake just the once and you've reset the switch too high

Mitchellinman, what fun symptoms! I think you have a different problem. As your headlights suddenly stopped working ( be a bit bizarrre if both bulbs went at the same time) then i'd be looking for light switch/ light switch connector problems or bad earths. I'd check out the indicator/ light switch connector at the steering column as the light switch is turning on the brake lights by the sound of it.

You didn't make clear what happens with no lights on and brake pedal on/ off

Also, are your tailights going on properly when you select sidelights or headlights? If not then you might have a bad earth at the rear of the car

It's kind of weird but the way the brake lights work is that the lower brake lights are fed directly from the brake light switch but the upper brake light is switched on by the body computer when told to do so by the brake light switch. That's why you can get lower brake lights off and upper brake lights on/ off combinations

Have you or anyone recently changed a brake light bulb? Sounds like a short circuit.

Also, your brake light switch might benefit from a quick adjustment.

EDIT: Damn Decks, you're quick!

What me? I'm told I have a slow hand

Cheers for the replies guys, The headlights went about a week ago so i do not think that had anything to do with this recent problem. What exactly happens is the 3rd brake light is on constantly whether the lights or brake pedal is pressed just constantly when the ignition is on. Now when the headlights are turned on the tailights come on as normal with the 3rd brake light on constantly as said before however if i press the brake pedal nothing happens atall, it could be that the bulbs both went at the same time however very strange. I noticed it yesterday as i had to do an emergency stop due to an absolute idiot doing the same to allow someone to turn down a side road while we were doing 30mph with no traffic infront or behind me very strange and then at the next lights while waiting for them to change a car pulled up beside and mentioned my brake lights were on constantly , so im thinking it may be somthing to do with the switch as mentioned above as i had to really brake hard and skided etc.
Cheers again guys

Let's say that your brake light switch has caused the brake lights to be turned on constantly and your lower brake lights have burned out. This would give your present symptoms of high level brake light on permamently and no lower brake lights when you use the brakes. I would have expected the "Warning stop light failure" message to have appeared though if you had just bulb failure.

You might just need a new brake light switch.

ADJUSTING THE BRAKE LIGHT SWITCH
Try adjusting it first and see if anything happens. Remove the over foot cover to gain access to the brake light switch and adjust it by pushing down on the brake pedal and pull the brake light switch centre plunger out further with some long nosed pliers. You'll feel it clicking. Then just carefully release the brake pedal without pulling the pedal up.

CHECKING
Open your rear hatch so you can see your hi level brake light
Check it now by putting on your ignition and hopefully upper brake light should now be out. Apply footbrake and see if the high level now works properly. If this isn't happening then you probably need a new brake light switch

ELECTRICAL CHECKING
If you're handy with a multi meter you could remove the switch and check it for continuity once it's out. Bit of a bitch to get physical access to remove it though. Have a look in the sticky up above "Brake light switch ESP etc"

REAR LIGHT CLUSTERS
Have a check of the rear light clusters too, someone had a rear light circuit board melt with the heat of their brake lights being permanently on, that might have happened as a knock on effect of permanently on brake lights

Update:
Took the car into lucas auto electricals today, the problems are as follows:
The brake lights bulbs all had gone and very badly gone they said, the brake light switch had completely broken (smashed apart was his wording) and he said due to this the lighting circuit was producing too much electric within the circuit so was regulating the current. he is also replacing the both headlight bulbs including the brake ones within the hour labour charge (which is £40)
Overall slightly annoyed as it was probably down to the stupid woman who did an ermergency stop and then when horned decided it was my fault and stuck the "V" up, however im glad it wasnt anything major as im driving to liverpool for a city break to venice tommorow so im glad its sorted.
Many Thanks again guys

Wow! We were spot on with our diagnosis

I suspect that the woman who did the emergency stop that you "horned" was a white witch and you and your car are now cursed.
Venice you say? Bon voyage

Well that's one set of lights sorted!

Now onto the reversing light! Thanks D5!