Maybe an NAS thing, but my fogs don't come on without my low beams on. Maybe even Canadian specific, as we have DRL's and the US doesn't.

Hi Harv, I think that the same rules may apply in the UK and Ireland, but I am not sure. I had a feeling that fog lights turn of when main beam is switched on, but I bow to anyone who can clarify this.

Gilbert, I was thinking that the problem with new headlights is that they are not focused in any way, they are positioned in the factory but nothing actually directs the beam of light. On old headlights, as everyone knows, there are the glass "lumps" or whatever you call them, and it is these that direct the beam of light. I just feel that a 100 watt bulb with a glass lens can give better light by being able to direct the direction of the beam, whereas the new clear plastic lenses don't have any focusing ability.

New headlights are really just like a torch, it depends how you hold the torch depends on where the beam shines.

I have a 1983 Mercedes W126 with 60/55 headlight bulbs and the lights are very good, as are the P38 headlights. I am happy with them.

Pierre3.

When the foglights can be used can be set in the BeCM, there's multiple different options so they can be switched on with just sidelights or with dipped beam or only when the rear fogs are on and so on. I think it used to be a case that front foglights could be used with sidelights and dipped beam but went out when you selected main beam. The theory being that if the fog was light enough that you could use main beam without the reflected glare dazzling you, then you didn't need foglights on. Mine is set in the BeCM for sidelights and dipped beam so may well go out if I use main beam, I've never looked to see. The problem I see with the DLRs on some cars is that they are much like a bright sidelight, so no beam setting at all, just a bright blob of light. I've taken cars with modern type lights in for MoT and the cut off is very sharp and is done on the back of the lens rather than an old school reflector and relying on the form of the outer lens. Always amuses me when sitting in the queue to get on the ferry and you'll see people trying to work out where to stick the beam benders on their plain plastic light covers.

Modern headlights have also lesser quality reflectors (thinner plastic walls), poorer chrome (due to the "ecological process"), thinner wires (so save money, more than weight), and flimsy electrical connectors (which give poorer power until they fail).
It is a natural that their output decays much faster than older design headlights ... I have a guy that refurbs lights for a living, very good, and he hates to do modern car headlights, he said they are nearly impossible to return to factory, and expensive parts as well.

I read sometime ago, when I had a Mercedes E220 with LED headlights, that if the light packed up you were facing a bill of around £300 to get it repaired/replaced. I believe that it had something to do with the power source that is needed for the light, but maybe I have that wrong.

Fortunately, I never had to find out.

The biggest problem I see with new cars and plasdtic headlight covers is that they go opaque after 6 or 7 years. You regularly see, for instance, a lot of 2001 era E-class Mercs with really dull and dim headlights, and when you look at them in the daylight it is almost impossible to the bulb !!

I bought a German-made 2 pack repair kit to bring mine back to near factory condition. A fait bit of work with different wet and dry sanding and then mask off the front of the car and spray a clear laquer on the lens. You then use a light resistant top coat to prevent the sunlight dulling the finish again. The one thing about this kit was that you could only use the one time, and work quickly. Once opened the finishing coat was on a rapid countdown of a few minutes after which you just have to chuck it in the bin.

But on a plastic lens the results are brilliant and very long lasting. Unfortunately, I haven't got a record of the kit that I used. I think that I gave away the paperwork for it when I sold the Merc. Pity !

Pierre3.

Having had a look through old computer records I may have used this product. It certainly uses the same process.

https://www.amazon.co.uk/Spray-Max-Primer-Lacquer-684099-Headlight/dp/B0147DESJ4

The wet and dry sandpaper needs to be fromsomething like 180 grit, to break down the yellow film, and working through finer grades, with a battery drill or screw-gun or just by hand, using P400, P800, P1000, P2000, P2500, and finally P4000.

[Edited to show to correct headlight restoration product]

Pierre3.