My car is booked in for a MOT tomorrow. Whilst checking the lights I found that one bulb didn't seem to be working for the rear lights. Its at the top of the 'C' on the bit that cuts across towards the bonnet (so above the reverse light), on the passenger side.

When the brakes are applied it appears to light up as a brake light, but during normal 'lights on' operation it doesn't seem to light up. On the drivers side it does light up.

As I do have lights on both sides (sidelights), and three brake lights - is this one bulb likely to cause me any problems MOT wise? Nothing is shown on the instrument cluster, bulb out wise either.

Many thanks,

Andehh

As a rule of thumb, if it is fitted then it should work, things like front fog lights are excluded as they do not HAVE to be fitted.

Change it now to save yourself grief.

The rear bulbs are very easy.

Your Octavia (2006) is fitted with dual filament brake/tail lights (later versions of the Octavia changed to single filament bulbs whereby the current is altered by the CANBUS depending on which function is required).

The Octavia has four tail lights in each cluster. From the top of the 'C' down they are as follows:

1) Brake / tail

2) Tail

3) Tail

4) Fog / Tail

Bulbs 1 & 4 are dual or twin filament (21W/4W) and bulbs 2 & 3 are single filament (W3W).

You need to replace bulb no. 1 as this is an MOT failure.

Make sure you get 21W/4W bulbs rather than the much more popular 5W bulbs otherwise this (can) throw up a bulb-out warning light. I fitted 5W bulbs for 2 & 3. These aren't monitored by the bulb monitoring system so I didn't get a warning but they only lasted 6 months and popped so I swapped back to W3W's.

Saying that I had bulb no. 3 out for my recent MOT and the tester never noticed. I think as long as he see's some 'red' from any of the four tail lights he's happy! Having three working brake lights is essential though.

Bulbs 1 & 4 are here (reverse and indicator too):

Bulbs 2 & 3 are here:

Edited 2 September, 201213 yr by silver1011

Just pick one up from Halfords, make sure it is the correct one, take out original as their book is wrong

If it's a light with more than one light source, the MOT rule is that at least 50% of the light sources have to work. So if it's a rear position lamp on an Octavia 2 with four light sources, then 3 of the light sources need to be not working to get a fail.

Really? I never knew that.

I always thought that 'if it is fitted' then it has to work.

A rear fog light isn't a requirement on some cars (so it can pass), yet if one is retro-fitted but it doesn't work the car can then be failed.

Edited 2 September, 201213 yr by silver1011

Just pick one up from Halfords, make sure it is the correct one, take out original as their book is wrong

+1, the Halfords bulb selection book is wrong for the Octavia!

Rear fog lamp requirement is for cars first used on or after 1st April 1980, if one was retro fitted to an earlier car and it didn't work then it would be an advisory rather than a fail. The same applies to indicator repeaters, I have noticed that on the Ford Capri these can be present or not depending on when the car was made, some people fit the earlier wings to these without the holes for the repeaters and then fail the MOT.

Rear fog lamp requirement is for cars first used on or after 1st April 1980, if one was retro fitted to an earlier car and it didn't work then it would be an advisory rather than a fail. The same applies to indicator repeaters, I have noticed that on the Ford Capri these can be present or not depending on when the car was made, some people fit the earlier wings to these without the holes for the repeaters and then fail the MOT.

Ah cheers was getting confused there as with my old 300ZX and all jap imports I have ever seen they have had to have a rear fog light fitted for MOT most look horrid but a very good thing to have if used at the appropriate time (like at 3am this morning on my way to Frankfurt total white out).

Andehh if a bulb is broken just replace it if in Halfords might be handy to find a bulb kit that suits the car (as said not off their book) if ever pulled by police for a light out you would stand a much better chance of getting off with the 3 points and the £60 fine if you can rectify it there and then.

Rear fog lamp requirement is for cars first used on or after 1st April 1980, if one was retro fitted to an earlier car and it didn't work then it would be an advisory rather than a fail. The same applies to indicator repeaters, I have noticed that on the Ford Capri these can be present or not depending on when the car was made, some people fit the earlier wings to these without the holes for the repeaters and then fail the MOT.

You learn something new on Briskoda every day!

Thanks guys, what might have happened is I replaced the original bulb with a ignal filament 5w bulb. Would that cause it to light up only for the brake lights and not for the sidelights?

http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_171165_langId_-1_categoryId_165538

That looks to be the one! Ill nip out and let you guys know when im back!

thanks

Edited 2 September, 201213 yr by Guest

The rule of "if its fitted then it must work" is generally the case for the Road Traffic Act. Unfortunately, just because it passes an MOT doesn't mean to say it is not illegal to use on the road!.

The penalty would be a rectification notice or at worse a £30, non endorseable ticket, not £60 and 3 point as previously posted.

A handy link to the MOT testers manual...

http://www.motuk.co.uk/manual/mc_contents.htm

Edited 2 September, 201213 yr by Metblackrat

Bulb bought and replaced and its all good! Thanks guys

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