3rd Brake light flashing problem

Lychee

The 3rd brake light (top of rear window) on my 2002 Corsa started flashing on & off the other night - but only when the headlights were on. Don't think there are any problems with other lights.

Does anyone know what the problem might be caused by & if i can easily fix it?

Grateful for any help.

Rolandtheroadie

Changed any bulbs recently?

Lychee

Not changed any bulbs recently myself. Bought the car in March. The lights stop flashing when I do apply the brakes, then it goes back to flickering on and off whilst the headlights are on. Goes off when headlights are switched off. It's probably a wire somewhere?

Kilty_2

Sounds like a dodgy earth somewhere

Lychee

I did read that somewhere. I've yet to try opening up the light myself, is it safe to try and fix it myself??

Outpost

Disconnect the bloody thing!

asbokid

Lychee wrote: »

The 3rd brake light (top of rear window) on my 2002 Corsa started flashing on & off the other night - but only when the headlights were on. Don't think there are any problems with other lights.

Does anyone know what the problem might be caused by & if i can easily fix it?

Grateful for any help.

Is the lamp unit factory-fitted or was it an after-market addition?

And are you sure that the unit is only a "brake light", and not a tail light, too?

Otherwise, it is difficult to understand how the lamp could become energised without the brake being applied.

At a guess, the lamp is fed by three wires. There will be a common earth, one wire to power the stop light circuit, and a third wire for the tail light circuit. The fault sounds pretty rudimentary.

marlot

It could be a faulty bulb in one of the 'normal' brake lights - if the filament is starting to come apart and shorting from the sidelights to the brake light circuit - so energising the brake lights. for the cost of them, I'd change both normal brake light bulbs and see if it still does it.

Or it could be the wires into the tailgate have worn through their insulation and are starting to short. Its more normal to get broken wires though - this is quite common on estates and hatchbacks.

Strider590

Some cars, the 3rd brake light flashes when the ABS kicks in.....
Also possible if the car has an ABS fault and had it's ABS warning light removed to get it past the MOT or to sell it on.

Easily check, just slam on the anchors and see if the wheels lock up

Doesn't sound like your issue (hopefully) but its worth a mention.

Lychee

Thanks for all your replies so far

we know the history of the car, so nothing dodgy happened at any point!

Update to the problem - all three brake lights are now constantly on (when the headlights are on). There is only a tiny amount of flickering, but hardly any worth noticing.

I hope this makes identifying the fault easier?

Stigy

asbokid wrote: »

Is the lamp unit factory-fitted or was it an after-market addition?

It'll be factory fitted on that era of Corsa.

Lychee, sounds like a wiring fault, typical of a broken wire. It'll be an easy diagnosis for a competant Auto Electrician.