regulations regarding wiring in spots/driving lights/ fog lights

picture for Martyn (just left of the number plate) -

i have wired in the most important bits first! :)

that's a mighty horn you have there (oooh errrr, missus)

You have to diferentiate between fog, driving and spot lights. Any lights that exceed the max for standard headlights (i.e. spot lights) are legal if they are wired such that they only come on when main beam is on. There are regs about maximum and minimum heights etc for head/fog/driving lights that would presumambly apply to additional ones.

Richard

how do i diffrentiate between my front lower spots being driving lights of fog lights then? im not sure they actually had that high a wattage bulbs in. they bay have only been 60w.

if i had them wired so that they were off/on with main/on always would that be MOTable?

I think it's something to do with the "shape" of the beam - fog lights are intended to give a beam that will cut through the fog and are quite bright (hence they can't be used when it isn't foggy), driving lights are quite diffuse, and their only function is to warn other road users about the driving standards of the driver ;-)

Generally speaking, if they come only with main beam then you've got no problem, if they can be on at other times then it would depend on whether they are fog or driving lights - not that I've see an MOTer check that that I can remember!

Richard

Fog lights are a spread beam usually below 500mm from the road and only to be used 'in conditions of fog and falling snow'. I can't see that these can't be switched separately as it is pointless to blinded by glare from your own headlights in the fog. I would think the lights would be above this height on a 101" so I would treat them as spot/driving lamps. As has been said I think they have to be switched in with the main but can be switched off separately. Also I think you can have unlimited wattage on a vehicle registered before some lighting regulations from around October 1978 came in but not sure on that!

Martin

On or around Tue, 18 Jul 2006 18:16:49 +0100, Tom Woods enlightened us thusly:

front fog lights: only for use INSTEAD of dipped beam in conditions of reduced visibility - generally accepted this means less than 100 yds. Most vehicles are wired so they come on with sidelights or dipped beam, though. Should have a warning lamp on the dash - I would make it law that they can only be on with sidelights and that the dipped beam and front fog lamps are mutually exclusive, if it were my choice...

Driving lamps/spot lamps: any number allowed and can be switched individually but all lamps over 7W must go out when you switch main beam off, i.e. when dipped or on sidelights.

All lamps must form symmetrical pairs when illuminated.

You can have chapter and verse of Road Vehicles (Lighting) Regulations 1989 (I think) if you want. The above is a quick summary.

On or around Wed, 19 Jul 2006 12:02:46 +0100, "Oily" enlightened us thusly:

front fogs can be at any height these days but dipped heads must be between

500 and 1200 mm from the ground, IIRC. It's against C&U to have front fogs and dipped heads on simultaneously, I think, and it's also pointless unless you're a chav.

If it's foggy enough actually to NEED the front fogs, then dipped heads are no use. FWIW, you've got to be talking the sort of fog that you can't see as far as the normal dipped beam pattern goes before front fogs are really useful.

Actually, the main use of front fogs these days seems to be to allow the rest of us to identify chavs at a quick glance.

That's because you're only allowed one pair of lights when on dipped beam but it wasn't always the case IIRC

But we don't get those sort of fogs anymore though and the fog lights were usually yellow to reduce glare.

Now you've made me spill my tea!

Martin.

On or around Thu, 20 Jul 2006 00:22:36 +0100, "Oily" enlightened us thusly:

My work here is done :-)

I wonder how many MOT testers check such things?

I have roof mounted lights wired to the main beam, but I wonder if anyone would take any notice if they were not.

The point with fog lights is to cast a beam with a flat low cut off that should not dazzle. The problem with driving in fog on ordinary lights being that the water droplets reflect the beam back to oneself so the point of fogs is not to avoid dazzling other road users so much as to avoid dazzling oneself. For an effective (rather than legal) fog light the height is dependant upon the vehicle, however I would suppose that it makes sence as a matter of general principle not to have any light that can dazzle oncoming traffic, that cannot be extinguished when one dips.