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MG MGA - Fog and Spot Light Legality

I must stop reading these archive articles that I am converting for the the MGCC.

If the law in the UK has not changed in the last 10 years it would seem that my lighting system is illegal, unless, of course our cars are exempt because of original wiring design.

Apparently our spot and fog lights should be wired through our headlights (mine are not) so that they cannot be separately illuminated. This is because a single spot or fog light could be mistaken for a motor cyclist. We should also have a panel-mounted warning light showing when they are illuminated.

Well, I am guilty on both counts it seems, unless someone can tell me otherwise

Steve Gyles


my fog/spot lights are wired through the headlight switch. It may not be original though.

Dan Smithers

Steve, that's what the UK law said about the mounting of fogs & spots just before I left the UK in 1983. Somewhere I have this documented at home. Don't know if the law changed since then, but I very much doubt it. Can't you check with DVLC in Swansea?

F Camilleri

I use two Lucas 576 spot/driving lamps wired up in a four headlight arrangement - they only come on when main beam is selected and go off when on dipped beam. Makes for a good driving experience at night, like a modern car, and never need to separately switch the spots. In fact, can't think of any time I have wanted to have the spots switched on on their own anyway.
The four headlight arrangement does need the use of relays, though, as there is a lot of current flowing for all four lamps.
Bruce Mayo

Hmmm. I wired mine separately so that I had the option to use them as 'flashers'. Seems I need to rethink the wiring, although the MOT people have never said anything - they probably only switched them on and off with the headlights already on and never tried the switch separately!

What have you all done about the required dashboard warning light?

Steve Gyles

Steve, If the spots are wired through the high beam circuit the warning light is your existing high beam indication light.
You will have to also fit a relay as Bruce (above) has.
Barry Gannon

Talking legality, huh? Regardless of the law, it is a very good idea to put pencil beam driving lights (spot lights) on a relay to drop out when the headlights switch to low beam. I'm sure all countries have a law requiring you to dip the headlights for oncoming traffic, so the spotlights must be switched off when you dip the headlamps.

I intentionally circumvented this arrangement once about 20 years ago. I was for a while driving regularly in foggy conditions in the dark. For this I mounted a pair of rectangular spot beams below the front bumper (other car, not MGA) with dead level spot beams, and connected to a separate switch. This was marvelous for driving in the fog, switch off the headlights and turn on the low mounted spots. The spots would cut under the fog (so to speak) for good long range illumination and very little reflective glare.

I think I violated a few laws with this setup. The spot lamps may have been mounted too low to be legal under modern laws, they were not wired directly to the dipper switch, they may have been 100 watt lamps, and I seldom ever installed the plastic covers.

One must be constantly aware of the setup and operation. Oncoming traffic then requires simultaneous switch on of the headlight low beams and switch off of the spots with two different switches. One night I forgot and pulled out of the fog onto an expressway, promptly getting a state trooper really PO'd with the bright lights and resulting in a bright spotlight shining in my face. Luckily the cop was on opposite side of a divided highway with no place to turn around, but I certainly got the message.

This arrangement could be done safely (more safely or less hazardously) using a couple of relays. Aside from using a relay for the spotlights in the normal manner, another relay and switch could be used to (selectively) disconnect the high beams when the spots are switched on. Then the normal dipper switch could kill the spots when the low beams come on, effectively using the spot lamps in place of the normal high beam headlamps. This may be of some interest to those retaining the original generator.

As a side note, I believe 100-watt headlights are illegal in Illinois (not sure about other states in the US). Such high power lights can only legally be used off road. Not only that, but those lamps must be covered any time the vehicle is on a public road way. So it is common to see accessory plastic covers or cloth socks for the spot lamps.
Barney Gaylord

My Twin fog/ Spot come on together via the fog switch only with the sidelights or headlights on. I only ever use them in conjuntion with the sidelights in poor visibility (as headlights are blinding in foggy conditions.) Surely thats the object of fog lights to give a low beam in adverse visibility otherwise whats the point?
P D Camp

Front spot/fog lights aren't a MoT item. Rear fog lights are (if fitted).

I sometimes hang around and watch - mainly for the entertainment of the "your handbrake doesn't work" and noticed that they didn't switch them on so I asked the mechanic.
Dan Smithers

Interesting point about the panel indicator. Over here, new vehicle requirements apply only to new cars. They are never retroactive so that you would never have to change a car's original design. If the car was originally in compliance and had no panel indicator, such as the MGA, no new legislation would require it to be changed. I can still legally drive an MGA with no seatbelts, only a single circuit hydraulic brake system, and no third brake light; even though the law generally outlaws such things. People still legally drive Model T Fords with cable brake systems, no turn signal lights etc.

Re: Barney's setup, I seem to recall that I could turn on the fog lights of my '95 Chevy pickup by turning the main light switch to power only the running (parking) lights. Then I could turn on the FOG lights on and off at will. Headlights would be on in DRL mode only. When I flipped the light switch to headlights on position, then the fog lights would be on/off depending on the high beams or not. Turning the main light switch totally off, would disable the fog lights. This came in handy not only in fog, but in a driving snowstorm too.
Chuck Schaefer


It is essentially the same over here. However, if you choose to fit any modern equipment, such as seat belts, they has to be compliant with current regulations.

The one lighting regulation that is retrospective is all vehicles are to have at least 2 red rear reflectors.

Steve Gyles


The The Road Vehicles Lighting Regulations 1989 are at:

The relevant section seems to be:

Section 6 -Optional Front Fog lights. Para 11 Tell-tale - no requirement.

So I don't think you need a warning light.

I also always thought that as you said, the fog/spots should be wired so they could not be turned on independent of the headlights but I can find no mention of this in the regulations. The regulations seem to imply though that if used in place of headlights then two fog lights must be fitted and within 400mm of the edge of the vehicle.

Having said all that, the regs only seem to apply to post 1991 vehicles anyway.

Malcolm Asquith

This thread was discussed between 06/01/2011 and 07/01/2011

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