Technical Rear foglight turned off when disabling main beam?

[manuelmarque]

Dear all,

Not sure if the car is meant to do this by design - I Googled and checked this forum and can't find anyone reporting this issue!

This evening I was driving my gf's Mk2 2001 Punto in thick fog, and due to that I had the rear foglight on (it is the 1.9D base spec model so no front foglights). At some point I flicked the main beam on, but when I turned it off (going back to dipped beams) the rear foglight also turned itself off! (the amber light on the dashboard disappeared, at least) Pressing the button on the dash turned it back on, but it seems that every time I turn the main beam off the rear foglight goes out too.

It shouldn't be a fuse issue, right? (otherwise it wouldn't turn on at all)

The battery on this car is not in the greatest condition (normally goes flat if we leave the car without being used for a couple of weeks), so I'm not sure if that could be an issue (driving too much current? But if that's the case then surely the foglight would turn off when the main beam was flicked on!)

It could also be something the car was meant to be doing in the first place - but I have never come across that (my old Corsa does not do that, and I'm pretty sure my Uno does not do that either!).

Thanks in advance!

 

[oscar52]

Cant say if its meant to do it (I have never noticed on mine), but why are you driving with full beam headlights in fog??


In absence of foglights you should only use dipped beam, otherwise the light just reflects back towards the car off the fog.

 

[digger58]

I think you will find on most cars the fogs only work on dipped beam for the very reason stated above!

 

[Mad one]

The rear fog light on some cars will turn off if you select main beam (but not on others), however it should then come back on when you select dip again. So I believe there is a fault with the car.

As for driving on full beam, I do the same around here on the unlit bendy back roads ( lots around here ) as often the fog is very thick, then dissipates, or with the high banks on the side you end up driving in a sort of tunnel effect and high beam works well

 

[manuelmarque]

The rear fog light on some cars will turn off if you select main beam (but not on others), however it should then come back on when you select dip again. So I believe there is a fault with the car.

As for driving on full beam, I do the same around here on the unlit bendy back roads ( lots around here ) as often the fog is very thick, then dissipates, or with the high banks on the side you end up driving in a sort of tunnel effect and high beam works well

Yeah, I did have some areas where the fog was less thick and I was able to use the full beam. When it got thicker I turned them off (exactly due to that reason, you can't see a thing ) and that's when I noticed that the foglight had cancelled itself too. I hear a click of a relay whenever I switch the main beams on - so could it be that the relay for the main beam is triggering the foglights one? (in my Corsa and in my Uno the foglight switch goes completely in, whereas in this Punto it seems that the switch is just performing a latch action... I will have a look at the fusebox at some point (which I have yet to locate... is it inside the engine compartment?).

Thanks,
Manuel.

 

[g8rpi]

As stated, fogs should off with main beam on. On some cars, typically those with momentary or push putton switches, they stay off after power of or main beam operation. Personally I think this is excellent design as it stops people leaving their fog lights on when it's not foggy. A related, but not so good, design feature is cars with automatic headlights in day time fog. They don't comon automatically and it seems a lot of drivers of higher spec cars are not capable of doing it themselves.

Robert G8RPi.

 

[Ziggy122]

Sidelight (pointless candle lights)
Dipper Beam (main beam)
High Beam (Blinding fuc....)

Regarless of which of those 2 settings your on the fog lights will stay on
If you have Sidelights only (pointless tbh i just go straight to Dipped beams)
I believe all fogs turn off - Wish all cars did this as number of people driving for days with fog lights still turned on when its not needed is a joke

So going from Dipped + R.fog to sidelights normally turns them off

Ziggy

 

[digger58]

My 2 pet hates, ****..s who drive with their fog lights on, (especially in the rain) and those who go straight across rather than around a roundabout. As a retired Police Officer you would be amazed at how many people looked dumbly at me when stopped and shown the light on the dash for fog lights! As I say "You can't fix stupid".:bang:

 

[twistedTSD]

I think you will find on most cars the fogs only work on dipped beam for the very reason stated above!

If you turn on high beams when low beams and front fog lights are on, mk2a turns off the low beams automatically (until you turn off the high beams), so you drive with fog lights and high beams.

I have never noticed that it would turn off the rear fog light though.

 

[PuntoHowTo]

Several comments on here about main beams turning off fog lights, but I have to say I have never owned a car that turns off the rear fogs lights, on front main beam operation. Ive own and driven cars from almost every manufacturer and never known this to be a thing on any of them, there is no laws or rules about using main beams in the fog and if it is foggy you'll still need to be visible by cars following, so if it is a feature somewhere on a car it's a bloody stupid feature

 

[g8rpi]

OK,
Just checked. My Croma does not put the fogs (front or rear) off with main beam on, but they do go off with lights off and don't come back on unless re-selected. I still maintain that if the "fog" is thin enough that you can use main beam without blinging yourself, it's not fog and you should not have fog lights on. There may not be a law about this, but it the laws of physics and common sense.

Robert G8RPI.

 

[PuntoHowTo]

I still maintain that if the "fog" is thin enough that you can use main beam without blinging yourself, it's not fog and you should not have fog lights on. There may not be a law about this, but it the laws of physics and common sense.

Robert G8RPI.

Lots of fog around here recently and very used to driving long distances in what is best described as pea soup.

If the fog is thick then the main beams will improve your chances of seeing the white lines and cats eyes at a distance, put the main beams on and tilt them to the full downward position on the adjustor, it will then light up the white lines and cats eyes but not reflect back and blind you.

Fog lights enormously useful in very dark and rainy conditions, without fog, where the edges of the road aren't clear; and they help light up the sides of the road in the immediate area around the front of the car. I believe the law on that one is clear it says visibility below 100yards (or meters I forget) doesn't say it "has" to be foggy, just reduced visibility.

 

[g8rpi]

<SNIP>

Fog lights enormously useful in very dark and rainy conditions, without fog, where the edges of the road aren't clear; and they help light up the sides of the road in the immediate area around the front of the car. I believe the law on that one is clear it says visibility below 100yards (or meters I forget) doesn't say it "has" to be foggy, just reduced visibility.

Sorry we will have to disagree on that one. Use of front or rear foglights in rain is alnost certain to dazzle and distract other road users which is an offence under the road vehicle lighting regulations, not just a breach of highwaycode guidance.
Rule 114

You MUST NOT

• use any lights in a way which would dazzle or cause discomfort to other road users, including pedestrians, cyclists and horse riders.

RVLR regs 3, 24 & 25 Rule 226

You MUST use headlights when visibility is seriously reduced, generally when you cannot see for more than 100 metres (328 feet). You may also use front or rear fog lights but you MUST switch them off when visibility improves (see Rule 236).

Rule 236

You MUST NOT use front or rear fog lights unless visibility is seriously reduced (see Rule 226) as they dazzle other road users and can obscure your brake lights. You MUST switch them off when visibility improves.

I have never seen rain in the UK that reduced visibility to less than 100 meters (Have seen it in other countries though). Spray can do it but the correct method to deal with that is to slow down and increase the gap between vehicles. Putting on main beams in rain or fog reduces visibility due to scatering and diffraction of light. Rear foglights in rain are particuarly distracting to following vehicles. Please don't do it.

Robert G8RPI.

 

[jimboy]

Slightly off topic from the OP but for me on some modern cars that have rear LED lights it's like Blackpool illuminations to coin a phrase. Rear fogs are just the half of the problem as far as I'm concerned. Siting behind one of these knobs when stationary at night sitting on their foot brake is blinding. There's a tendency when turning left or right brake lights & indicator lights are all merged into one & at the last second, very annoying & dangerous if you get caught out.

 

[PuntoHowTo]

Sorry we will have to disagree on that one. Use of front or rear foglights in rain is alnost certain to dazzle and distract other road users which is an offence under the road vehicle lighting regulations, not just a breach of highwaycode guidance.

You can quote the high way code all you like, in fact there are forums dedicated to people who like to do this and the world of YouTube is full of keyboard warriors who will rid the world of those who would dare defy it.

However.... in this instance I am talking about front fog lights, the rear fogs are rarely used as they are the LED type which blind everyone behind me.

The front fog lights are the type which turn on and off with the indicators and when you apply a lot of steering left or right. They are designed on my car to illuminate the edges of the roads especially cornering, they do not dazzle on coming cars I know because I have been that on coming car many dozens of times with this make and model.

When it is pitch black going cross country on rural roads across Norfolk Suffolk and Cambridgeshire and my head lights projection is far ahead it leave a blank unlit area at the near side front which is very handily lit by the front fog lights l and for that I make no apology [emoji13]

Come for a drive in heavy fog in my car and I will show you how the main beams will light the road ahead using my previously mentioned method much better than just putting the fog lights on.

Light will disperse in heavy fog in all directions but throw enough light in one direction and it will light the way, the basic principles of how a lighthouse works.

Modern lighting on cars is a lot smarter than in the past, my car has auto main beams that turns them off when it sees other cars. An upgrade to that system uses mirrors to actually block the light from dazzling on coming cars and track the movements of those cars without turning off the main beams which it in theory completely illegal by the rules of the Highway Code.

The latest thing from Mercedes is head lights that will project sat nav directions onto the road in front of the car or illuminate specific features on the road like a crossing or paint a crossing in light for pedestrians.
Xenon lights LED lights laser head lights all illegal but still perfectly legal
Non of this is in the Highway Code! The world is moving on while dinosaurs are still quoting rules devised in the 1980s

 

[g8rpi]

None of the modern headlights you talk about are illegal. This is because they are covered by EU type approval. Becuase of this they are accepted in the UK even though they are not covered by the RVLR or even specifically banned by then e.g. Audi's "nightrider" indicators.
However driving with front foglights on when it is not reduced visibilty IS an offence in the UK. If driving at speed you should be looking ahead, not at what the foglights would illuminate because anything there is too close for you to react to. This is not rules it's physics and physiology.
The cornering lights are a different issue as the only come on one side and under specific conditions.
Robert G8RPI.