Checking the lights before the MOT.

Only the right hand side rear fog light works, but double filament  bulbs to both sides, when I switched the bulbs L to R(because the non illuminating filament looked OK),

still only the right side lights up.

So it is not the bulb, and hardly a fuse(not checked because it started raining and got dark, so I came inside), since ALL other lights are working. 

P.S.

Any DIY way to check the headlight alignment?

mth

 

That's as it's supposed to be.

 

With VCDS you can activate both rear fog lamps.

 

To DIY check headlamp alignment drive up to a garage door with the lights on at night and with chalk or tape mark the dipped beam cut off lines, reverse back, drive needs to be flat and compare/adjust. Best to Google for a proper description.

37 minutes ago, Wino said:

That's as it's supposed to be.

 

Wino,

Thank you for your answer, which, if I understood it, means the car should only have 1 fog light, on the right.

I appreciate that various manufacturers fit standard components, but the base model may not get the 2nd fog light reserved for the higher spec models in the range.

However both L and R lamp clusters have the same 5 wires connected up, and the L bulb holder unit has the double set of contacts for the twin filament bulb.

So I was perplexed.

Cheers,

Marcus

J.R.

Thanks, should have thought of Google/Youtube.

Don't think spec affects what works from the factory.

Edited 3 October, 20196 yr by Wino

1 Rear fog light does the job if on in Fog,

and are half as bad to drivers behind if mistakenly left on when no fog compared to 2 rear fogs IMO.

58 minutes ago, J.R. said:

With VCDS you can activate both rear fog lamps.

 

Not on a 2010 car with a BCM. You'll need VCP, ODIS-e or similar...

 

20 minutes ago, marcusthehat said:

However both L and R lamp clusters have the same 5 wires connected up, and the L bulb holder unit has the double set of contacts for the twin filament bulb.

 

 

Counter intuitively, it's because it doesn't use both filaments...

 

The lower power (4W?) filament isn't connected to anything in either the brake/tail or fog/tail lamps. Instead, the taillights are done by dimming the 21W filament. The brake or fog functions will cause it to run at full brightness.

 

Not sure about pre-FL cars but that's correct for all MK2 Octavia's with a BCM

 

Thank you Langers, I think?🤨

Anyway as long as I only got 1 rear foglight, I am good.

Edited 3 October, 20196 yr by marcusthehat

In a thread on here some time ago it was said that "the authorities" chose to differentiate between brake lights and fog lights by only fitting one fog light on the offside of the car. Certainly VAG have followed this on all models for many years.

10 hours ago, pikpilot said:

In a thread on here some time ago it was said that "the authorities" chose to differentiate between brake lights and fog lights by only fitting one fog light on the offside of the car. Certainly VAG have followed this on all models for many years.

Ah!

Ah well, I checked the dipped beam, per a Google link, and we got through the  MOT this morning, though I will soon need new rear brake pads.

Thanks all.

Edited 5 October, 20196 yr by marcusthehat