960 rear fog light

[Laird Scooby]

Originally Posted by jonnyf90

Fogs work with just side lights on.
In fact it’s illegal to drive in Sweden with dipped beam AND fogs. It’s one or the other

Cheers

The front fogs will work with sidelights or dipped beams only but the rears need dipped beam and/or front fogs. On mine, i have a two position foglight switch - first position brings front fogs on, second position brings rear fogs on as well.

Sorry to say it but you're wrong about the law in Sweden - i only know this as on another forum i talk to a Swedish member quite a lot and he was telling me recently it's illegal to drive without your lights on - regardless of the time of day. Front fogs can be used with sidelights only but it's "frowned upon", usually the law requires they are used with dipped beam headlamps as well.

The information is contained within a PM so i'm not going to post a link to it (not that i could as it's in my inbox so you'd need my log in details - )

As for the rear fogs staying on with main beam, that's pretty usual but the front fogs usually go off, they certainly do on mine unless it's just a flash.

[Stephen Edwin]

I don't think I have done a tautology or a pleonasm but if I have am I bovvered?

If I have read correctly, the thread is about high intensity rear lights. There are also front lights designed for use in fog, basically approximately with a very flat topped beam to reduce glare back from stray light.

Which lights, front, rear, are you talking about re Sweden please?

If visibility is sufficiently poor to need high intensity rear lights, then one usually needs either fog lights or headlights at the front, to be seen, and hopefully to be able to see.

[Stephen Edwin]

Interesting Dave re Sweden.

If one needs the very defined beam of front fog lights, it seems to me seriously counter productive to have the headlights switched on.

One could use headlights and front fog lights to get extra light when the very defined beam is not needed.

Hey ho.

I used to have a 740GLT. The inbuilt front fog lights were a godsend one difficult heavily laden early hours drive in fog up from Exeter past Stonehenge to Sarf Essex when I was going down with a deeply horrible chest infection. Actually that 740 (auto estate and a tough easy to drive car) helped me out big time that year. Don't tell anyone I said this but, I should have kept that car. I received not good advice from a good motor engineer, very good chap but past his prime. Is life.


.

[Laird Scooby]

Originally Posted by Stephen Edwin

There are also front lights designed for use in fog, basically approximately with a very flat topped beam to reduce glare back from stray light.

Not just a very flat topped beam but also a very wide beam to aid dispersal of the light through the frog.

Using full beam in fog will simply present you with a wall of light in front of you where it meets the fog, usually reflecting back at you as well, dazzling you.

These diagrams should make things clearer :



That gives the approximate coverage of the OEM lights including fogs and also additional (KC) lighting upgrades/additional lamps.



That gives descriptions of the various types of front lighting and the beam coverage to be expected.

Maximum height for a fog light is 1200mm from the ground but it's usual to fit them below the bumper - 760 facelift and 9xx owners take note - the front fogs are integral with the headlamps, on the 760 at the top half of the inboard part of the lenses and on the 9xx, on the lower half of the inboard part of the lenses. The former can be seen here on my 760, with the driving lamps on the bottom half of the inboard part of the lenses :



Interestingly there is no minimum or maximum height for additional driving lamps but that's just a useless bit of trivia as we're talking about rear high intensity fog guard lamps.

Most of the phrase is marketing hyperbole but...............

they are high intensity............................
they do "guard" the rear during fog...........
............it's fair to say the name is usually shortened to rear fogs, rear foglights/foglamps or similar. When i took my driving test, there was a question from the examiner - on what occasions should you use the rear fog lights?

The correct answer was in fog, heavy rain and falling snow.

The same applied to the front fogs but in those days, front fogs were only fitted to prestige and/or performance cars as standard. For example, the Rover SD1 3500, Ford Granada 2.8 Ghia/GhiaX, Vauxhall Cavalier CD/CDi and similar. Note the absence of Jags, Volvos, Rolls-Royce/Bentley, most German marques (i think some Porsches had them as standard when i took my test) and most cars on the road!

However, from July 1980, it was mandatory to have a minimum of one rear fog lamp, if only one it had to be on the drivers side (so the right here in the UK) or centrally mounted. As far as i'm aware, there is still no legal requirement for front fogs to be fitted but a few years ago i was told by my MoT tester that if they have been fitted, they must work.

[Laird Scooby]

Originally Posted by Stephen Edwin

Interesting Dave re Sweden.

If one needs the very defined beam of front fog lights, it seems to me seriously counter productive to have the headlights switched on.

One could use headlights and front fog lights to get extra light when the very defined beam is not needed.


.

The only defined thing about the fog light beam is the cut-off Stephen - the beam itself "fans out" and in doing so, diffuses to minimise refractive and reflective glare from the fog.

By comparison, dipped beam headlights are extremely defined, they also have a cut-off but additionally have a "kick-up" which illuminates the verge, pavements and street signs. Lights for this country are known as "LHD" - Left Hand Dip. Confusing as we use RHD as Right Hand Drive! It's the opposite way round in Europe but the USA use a slightly different system with a less pronounced kick-up :



Top there is USA so is Right Hand Dip for Left Hand Drive but with the DoT (Dept of Transport) kick-ups which are near flat.

The EU get the exact opposite of what we get which not only means they have different lenses but different reflectors so the bulbs sits at a slightly different angle to facilitate the kick-up. That's why halogen H4 bulbs have masks below the dipped beam (60W) filament to prevent the bottom part of the reflector from shining light upwards. No such mask under the high (55W) filament.
Yes, that is correct - because the dipped beam filament is masked partially, it uses the higher powered of the two filaments.

Bottom on that diagram is our UK beam pattern for EC conformity with the kick-up on the left to shine on pavements, signs etc.

[jonnyf90]

Originally Posted by Laird Scooby

Sorry to say it but you're wrong about the law in Sweden - i only know this as on another forum i talk to a Swedish member quite a lot and he was telling me recently it's illegal to drive without your lights on - regardless of the time of day. Front fogs can be used with sidelights only but it's "frowned upon", usually the law requires they are used with dipped beam headlamps as well.

Read it on here: https://korkortonline.se/en/theory/lights/

Knew about driving with your lights on all the time - much like in Italy where you must have dipped lights when outside a town or village

Cheers

[Laird Scooby]

Originally Posted by jonnyf90

Read it on here: https://korkortonline.se/en/theory/lights/

Knew about driving with your lights on all the time - much like in Italy where you must have dipped lights when outside a town or village

Cheers

That's interesting - i wonder if something was "lost in translation" or perhaps my Swedish friend is a little behind the times?

[Stephen Edwin]

Dave yes. Flat and wide was the basic description I learnt. In those days I was told there was a Ministry recommendation of two differently defined light at the front to use in fog.

On the right a "fog lamp", flat and wide. To avoid glare, the white wall yes. And to spread out to pick up posts and bollards and other such things whatsoever. Gosh and to see people!

On the left a spotlight, to light up the kerb or verge.

Those lights, especially is of a good make, were well defined. Headlights were er, not well defined in those days.

Nowadays headlights are yes well defined. Probably better that the old fog lights? And nowadays we have less fog, at least in part due to clean air regulations.

The last heavy horrid fog I personally encountered was in the second half of the1970s. (My litle experience is limited to fog. Smog was only just in my lifetime before anyone asks....)

.

[Stephen Edwin]

Originally Posted by jonnyf90

Read it on here: https://korkortonline.se/en/theory/lights/

Knew about driving with your lights on all the time - much like in Italy where you must have dipped lights when outside a town or village

Cheers

Now that I begin to understand. The issue is not side lights/parking lights, it is daytime lights. And it appears to relate to front lights for use in fog.

So dipped headlights and parking lights together are the norm in Sweden. Sounds good to me.

"Fog lights" .... lights at the front to use in fog I guess .... are not allowed with headlights. well that is my thoughts exactly.

Headlights or "front" fog lights with daytime lights, not allowed.

Those guidance notes don't distinguish specifically that I can see, but, they don't seem to prohibit high intensity rear lights from use with headlights.

Anyway I'm only curious. I won't be driving in Sweden.

The real issue is. Has the problem with the original poster's high intensity rear light(s) been actually solved yet?

[krismorgan]

Yes i have a working rear fog light thanks.And a very interesting read so thank you all.