OldShep56 wrote:

Have a look in your purchase history and you should find them, BPS

Glad I’m not the only lunatic up at this time, lol

It was in June. I buy all sorts from ebay so delete my purchase history every now and then. Otherwise it would be a massive list.

It may be a massive list but as proved in this case, it is one worth keeping. It doesn't sit on your server so it isn't taking up any space on your HD.

Took a quick look at E-Bay offerings. Total minefield. Many haven't a hope in hell of delivering any sort of controlled beam shape. Just a mess of chips shoving light everywhere.

You need something with a shielded dip beam source and LEDs both sides to be reasonably sure it will work as designed. This style looks as if it might have a chance E-Bay 282700261635. At least the dip beam source is shielded, although you need to turn the bulb unit through about 45° to get it in the right place, and the emitter is reasonably narrow so the light ought to come out through the right part of the lens to give a half decent cut off. The twist means the main beam emitters aren't really ideally aimed to make best use of the reflector so main beam pattern will suffer but it ought not to be too bad. Assuming the emitters are in the right place front to back.

If the pictures are right this one E-Bay 172804798178 is a decent illustration of what happens when the dip beam LED is both too wide and unshielded. Cut off? What cut-off. Probably in a more sophisticated headlight than ours too without the flat sections at top and bottom. The designers clearly considered that putting the LED pointing straight up meant its backing plate made an adequate shield.

Pictures on this one E-Bay 332400013805 give you some idea of how the shielded LED compares with a normal bulb. Only sort of similar. Wouldn't touch that one as its expensive and lacks a second main beam emitter on the backside. Which we need. Forget anything that pretty much implies motorcycle only. Different headlight pointing angle means you can get away with much more.

Clive

(Who many years ago suggested that non imaging collectors might be cheaper than a proper lens and scanner in a very low cost IR homing head. Promptly got told to go and spend a month or two figuring things out. For all practical purposes a headlamp running backwards with the detector in place of the bulb. Painful and hard to forget experience!)

Thanks Clive, Nightbreakers are back in now. I see what you mean about a narrow light source on the first ones..Although our light units are square, the actual reflector is circular and looks to be a standard parabolic reflector so will need a pinpoint light source. Much like how a satellite dish works to focus everything down to a single point.

I think what I'll do is leave the headlights as they are and try LED bulbs in the front fogs. When in France I tend to drive with them on anyway to give a bit more light directly in front of me so a bit more light from them wouldn't go amiss.

Warning Tech-Nerd Post

Given what I used to do to earn an honest (!!?) crust somewhat overdeveloped Rikki-Tikki-Tavi tendencies are probably inevitable. This rubbishy LED headlight bulb thing has annoyed me so much that I just had to "run and find out".

Basically its another thing we can blame the Americans for.

The American (SAE) standard for dipped beams doesn’t have a cut off. Dip beam pattern is very similar to main beam but directed sideways and upwards to reduce glare for oncoming traffic. Lower power too. Doesn’t seem to work wonderfully well as the American maximum legal headlight output power is lower than ours.

Getting the necessary difference in beam shapes with simple unshielded filaments is a difficult trick needing precise positioning. Several different styles of bulbs are used with various filament arrangements viz :- 9004, 9007, H13 and HB2 / 9003 suggesting that none are terribly satisfactory. The last one HB2 / 9003 is what causes all the trouble as it’s essentially the same as the our H4 but, allegedly, with tighter control on the filament position to give the SAE beam shape. Far as I can see the shield doesn’t actually do much in a SAE standard headlight except to confine dipped beam light to more or less one half of the reflector.

The common form of white LED emitter is a relatively large flat plate with an emission angle of around 120°. In optical terms its totally different to any filament. As such LED emitters are always mounted on an opaque plate with the dip source on one side only part of the reflector can used so a bit of twisting around should produce some sort of approximation to the SAE dip pattern almost regardless of the number, size and style of emitters. Might go a fraction better with reflectors intended for HB2 / 9003 bulbs as those are only supposed to use part of the reflector anyway. Nooging around American market LED bulb offerings it appears that pretty much every style of emitter can be found on every style of bulb base. Given that the SAE beam pattern is such a wishy washy thing they probably all work to varying degrees of near enough.

But in UK and European headlamps the shield, filament position and filament shape are vital if a proper dip beam cut-off and well behaved main beam are to be produced. So simply saying H4 = HB2 = 9003 and trying to sell the same mixture that suits the American market as H4 replacements isn't going to work. Simple large area emitters spray light everywhere it isn’t wanted as well as where it is, overwhelming the real beam with extraneous light. Narrow emitters giving a reasonable approximation to filament output patterns and properly positioned shield are essential to get anything like the proper beam pattern.

I'm tempted to put my money where my mouth is and give E-Bay 282700261635 a try.

The wikipedia article https://en.wikipedia.org/wiki/Headlamp is actually quite good although the optics pictures are very over simplified.

Dunno what shape our reflectors are but they won't be parabolic. Probably a smoothed out homo-focal set-up, which is a right bastard curve. Nearest you will find to true parabolic curves on rectangular H4 headlight reflectors are the old almost letterbox style ones with whacking great flats top and bottom.

Clive

I don't mind a nerdy post and it reads better than some of the stuff I have to wade through at work too. Reading that Wikipedia article explains why the ones I bought don't work (it also demonstrates the American 'not invented here' mentality). The dipped beam filament needs to be 1cm forward and 3mm higher than the high beam filament. The ones you suspect might work, definitely have the spacing something like although I suspect that the 3mm height difference isn't as much as that. The ones I got have a single large COB chip where one end illuminates for dip and all of it for main so the spacing is all wrong. Dip isn't far enough forward and is on the same axis so never are going to be any good.

I can vouch for the fact that US headlights are crap with the vehicles I'm importing from the US (there's a 1972 Volvo 1800ES sitting outside that needs taking to France next week). On most of them, they also have amber front sidelight/indicator units so I remove the sealed beam units and fit 7" round conversion units with H4 halogen bulbs and integrated sidelights. Then I have to disconnect the feed to the sidelight filament and run it to the separate sidelight bulb in the headlamp. There's been the odd one where the side/indicator unit doesn't use a single 5W/21W bulb but use separate bulbs so I can leave the sealed beam units in place and change the all amber lenses on the sidelights for European clear and amber ones. The US sealed beam units will pass an MoT as the flat splodge of light they give on dip is acceptable according to the testers manual but they are pretty piss poor for trying to see where you are going in the dark.