Had the brake light go a few weeks ago so replaced it, checked it's operation and no problem.

A little while later, I noticed the the upper side light elementhad blown on the bulb I'd recently replaced whilst the brale light was fine.

Miffed at the lack of life of the offending bulb, I went to replace it again only to find that the sidelight element hadn't blown, just glowing bery dimly. Tried another bulb and still the same. Cgecked connections etc but couldn't find anything. Other side lamps are fine and the sidelight on the side in question was fine also whilst the brakelight had failed.

Now the brake light is fine and the sidelight is the problem.

Any ideas folks?? :confused:

Excuse the spelling - my RF keyboard batteries seem to be on their way out lol!!

First thing to check is for a bad earth and/or corrosion on the contacts.

After that you need to get a voltmeter out to check whether yuo are getting the correct voltage to the bulb.

Silly question but we're all human!

Is it the correct bulb? I've 'accidentally' fitted an incorrect bulb in this way before, straight as opposed to offset pins which gave the same effect, just a thought!

Had a brake light fail on the Fabia today and got the boing!

Quick trip to Halfords, and sorted

Check that you have the correct bulb. I think that the Octavia II uses a single filament bulb for both the brake and tail lights and the computer controls its brightness by varying the voltage to the filament.

Silly question but we're all human!

Is it the correct bulb? I've 'accidentally' fitted an incorrect bulb in this way before, straight as opposed to offset pins which gave the same effect, just a thought!

Yep I thought I had the wrong bulb but fitted same as what came out - a twin filament stop and side light bulb, the pins are offset so will only insert and twist in one position.

Will check earth point fo corrosion / bad fit etc. Trouble is, one would assume the whole cluster shares a common earth so as to make the wiring harness less complex and save money - yet all the other functions (indicator, reverse,fog,brake and other side light bulbs) are ok.

thanks for the ideas chaps!!

Did this ever get remedied?

I have a very similar problem on my 06 vRS.

Top twin filament tail/brake bulb is only working on one filament. When the tail lights are on the filament glows incredibly dimly & lights up brighter when the brakes are operated. The other filament doesn't seem to do anything.

The bulb is the same spec as the one in the other cluster which works as it should.

I've tried 3 different bulbs (which are seemingly the correct spec with the offset bayonet lugs) to no effect.

The dash (non-Maxidot) is showing a 'bulb fault' warning light.

I suspect an earth fault or a wiring/electronics problem & seeing as how I only collected the car from the dealer today it's looking like it'll have to go back to be sorted but is there something daft I'm missing..?

Many thanks,

DW.

Probably not the cause but make sure that you are replacing the bulb with a 21W / 4W not the much more common 21W /5W.

For some reason the brake/tail and fog/tail are 4W on the Octavia. Using a 5W bulb is known to cause some strange symptoms.

Also as mentioned above older Octavia's use twin filament bulbs, however the latest Octavia's use single filament bulbs but the CANBUS system simply alters the power to the single filament to replicate the different functions.

Could the garage have replaced a blown single filament bulb with a twin filament?

Probably not the cause but make sure that you are replacing the bulb with a 21W / 4W not the much more common 21W /5W.

For some reason the brake/tail and fog/tail are 4W on the Octavia. Using a 5W bulb is known to cause some strange symptoms.

Also as mentioned above older Octavia's use twin filament bulbs, however the latest Octavia's use single filament bulbs but the CANBUS system simply alters the power to the single filament to replicate the different functions.

Could the garage have replaced a blown single filament bulb with a twin filament?

Cheers for that.

It is the older twin-filament spec & interestingly the bulbs are indeed 5watts on both sides, yet the other side seems to work fine..

Maybe the affected one is more sensitive..?!

Will try & get a 4watt variety & give that a try. Typically, I replaced like for like & even consulted Halfrauds' handy guide too..

:-/

The Halfords guide is wrong.

Another story but I have just replaced all of my rear bulbs and couldn't believe how inaccurate the guide is

I couldn't even find any Halfords own brand P21/4W and had to buy the Bosch ones instead.

Yes, just found that the Halfords guide is practically a work of fiction Le Carré would be proud of..

I managed to source 2 of the 21/4w Halfords bulbs & a Bosch one & now, touch wood, all is well.

Thanks very much for all the assistance everyone - this was taking the gloss off RS ownership & I really couldn't be faffed taking it back to the dealer after 1 day of ownership.

Fingers crossed all's now well in the lighting dept.. ;-)

Now all I need is for my Briskoda car sticker to turn up & I'll be a very happy bunny.

It's well worth the extra cost and getting proper VW long life Bulbs ( code LL on bayonet fitting). These last must longer than the cheaper suppliers.