Headlight dip switch

[englishmaninwales]

I thought it was OK to convert to LED Headlamps if the car was built before April 1st 1986. That ruling appears to apply only to later cars. Does anybody know the correct ruling. The LED suppliers seem quite confident in their products.
Also it may be that it only applies if replacing a halogen lamp, not a tungsten filament type like ours.
Eric in Burnley
1967 S3SE DHC

Thanks Eric, I suspect you’re correct, the replacement of original tungsten bulb is how the LED replacements get through.
My car is going for an MOT on Saturday, I shall ask my usual MOT tester on his view of the rules.

[Bigbaldybloke]

I believe the LED conversion has been clarified for uk MOT, you cannot just fit LED bulbs into an existing headlamp unit, but you can fit a complete LED headlamp sealed unit. Several uk suppliers are offering suitable units as complete replacements, looking at them and also units offered on eBay it looks like they are using headlights originally intended for a Landrover. These units contain not only the headlights but also sidelights and indicators that could be wired up and used if you wanted to, these are in a halo effect around the main lamp a bit like BMW used to fit.

[Quart Meg Miles]

The reason the dip switch fails isn't the 8 - 9 amps running current, it is the starting surge which may be five or ten times higher as the bulb filaments get up to white heat.

Neither of my column switches are original but they haven't given trouble for at least 30 years/100,000 miles. I had a 205 GTi that wore down its dip contact but I was able to swap it over with a spare one.

I took the wood out of mine early on so I could run with the lamps up but not lit. Soon after, I used that position to run the lamps in a low-current dim state using a relay to put the filaments in series; I was driving through rush-hour traffic every night and fitted repeater flashers at the same time.

[englishmaninwales]

Thanks, am I correct in thinking LEDs do not have an initial current peak as high as filament bulbs?

I’ve spoken now to my MOT tester who said he would pass any LED headlight replacement in the Elan, providing they both work, both dip properly and the spread/aim is correct. I think the sealed LED unit is the route I shall now invest in.

Thanks to all the contributions, most helpful and have improved my auto-electrics!

Malcolm

[ericbushby]

Thanks for the update Malcolm. That is very useful.
My car is all LEDs except headlamps and ignition warning. As I have only driven at night twice in ten years, it seemed extravagant to change the headlamps, but now you might have given me an excuse. I can get better lights, save my dip switch and it is no longer necessary to fit relays.
Eric in Burnley
1967 S3SE DHC

[Quart Meg Miles]

Thanks, am I correct in thinking LEDs do not have an initial current peak as high as filament bulbs?
Malcolm

They don't have any at all! The current passes and they emit light.

[elancoupe]

Thanks for the update Malcolm. That is very useful.
My car is all LEDs except headlamps and ignition warning. As I have only driven at night twice in ten years, it seemed extravagant to change the headlamps, but now you might have given me an excuse. I can get better lights, save my dip switch and it is no longer necessary to fit relays.
Eric in Burnley
1967 S3SE DHC

Can you provide a link to these LED lights? TIA

[ericbushby]

Hi Mike,
I used `Classic car leds` Just google that and you will find a web site and catalogue.
I found the listing a bit complicated and confusing, but Duncan there is very helpful and will make sure you buy the correct bulbs.
best of luck
Eric

[ericbushby]

Hi All,
I have finally found an answer to the current drawn by an LED headlamp.
The classiccarleds website states 1.8 Amps compared to 5 Amps for a Halogen bulb so I am now confident that relays are unnecessary.
Eric in Burnley

[oldelanman]

I am now confident that relays are unnecessary.
Eric in Burnley

Without relays how will you ensure the lights are off when the pods are down?

[ericbushby]

Hi Roger,
It will be just as it is already. On my S3 there is a switch for the headlamps and a vacuum valve to raise the pods.
It relies on the driver to switch things off.
I am not familiar with the S4, but if you already have relays then it will continue to work using them and the pod switches if you have them and want to interlock it.
My point applies if relays are not already fitted then it is not necessary to fit them or do alterations to the wiring loom. The lamp current is low enough to not damage ageing dip or panel switches which at present carry full lamp current of 8 or 9 Amps. (ish)
Eric

[oldelanman]

Hi Eric,
I thought all cars had relays and microswitches, S1&2 a single relay in the feed to the dip switch and S3&4 two relays downstream of the dip switch .. that's according to the wiring diagrams in my workshop manual. Surprised your S3 has none.
I understand your point about the lower current with led lamps not needing relays to protect the switches.

[ericbushby]

Hi Roger,
No relays on mine so the lamp current goes through the panel and dip switches, which brings us back to Malcolm`s original question at the start of this thread.
Yes, I also have the wiring diagram and I have the car and they are different. Have we come across this sort of thing before?
Eric
1967 S3SE DHC

[englishmaninwales]

Eric, sorry if I’ve mis-understood your last post, but my installation and diagram, the dip switch on S2/early S3 is downstream of the single relay, hence the switch carries the full or dipped beam load; the later S3 diagram (and presumably S4) show the dip switch upstream of the twin relays.
Malcolm

[Quart Meg Miles]

...and the relay of the early cars relies on the RH pod "microswitch" to ground it. I've never had a problem with it which is just as well as it's the only thing that does switch it on in my slightly rewired car.