Lotus Elan

Bulbs specifications and conversion to LED

PostPost by: LotusEngineeringBuff » Mon Jul 09, 2018 6:40 am

I am happily driving my Plus2 after x years of storage and 1 1/2 year of resto/reconditioning. It got a fresh Swiss MOT and I am now in the shake down period I would say. One of the remaining problem is that the headlights thermal cut-off switch fires after 10-15 minutes. I found it kind of funny the 1st time because it was not pitch dark and I was on a quiet road. But not so last week when I was with passengers (2!) on the highway.
I did not want to go back to rewiring the additional large section wire across the engine bay and relay so I thought LED.
Being on this track, I thought I might as well do a full LED conversion. The document attached could save you the time it took me to put the information together in case you want to go that route too.

I'll let you know in August how things are working

A) The links for the LED procurement will soon be outdated because this market is evolving very rapidly
B) I know that I might not be legal presently to have LED headlights. Law is slow to adapt. I do not doubt that in the close future it will. And if its not, I'll just revert to std H4 for MOT testing when the time comes.

Until then have a nice summer

List of the Lotus Elan bulbs with original numbers, current numbers and LED links
(49.17 KiB) Downloaded 89 times
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PostPost by: gherlt » Mon Jul 09, 2018 7:30 am

I have doing research on this for my two seater and bought two led 7" headlamp sets, both advertised as "legal". Both are sold mainly for land rover defender.
One is from eBay UK, seller originalcaferacer. It has an ECE marking, but in Germany MOT/TÜV told me, to be considered legal they are missing the allowed use (some letters) and the certificate numbers, usually 5 digits.
Otherwise good looking, well made, perfect fitting, good light. Beam is a bit strange. I'm original position the beam is a wide angle \/, not as it should be (lhd _/ , rhd \_). Answer was "turn it a bit" if I understand correctly.

The other one is from truck lite, they have the markings, so should be legal.
http://www.truck-lite.com/webapp/wcs/st ... reId=10001

But ... Not sure how tell this, the glass is far more forward from mounting ring than the normal headlamp. Fits perfectly, but glass blocks closing movement of the bowl. No chance. Also a bit heavy.

There a few more headlamps, but the looks are too modern.
20180709_091839.jpg and
Truck lite side view
20180709_091816.jpg and
Truck lite
20180709_091337.jpg and
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PostPost by: Frogelan » Mon Jul 09, 2018 1:44 pm

I'm rebuilding a 1965 S1/2 from boxes, E**y...and the 3 main firms for Elans.

When looking at the headlamp situation (LHD / for EC compliance), I decided that none of the LED possibilities are close enough to being EC road legal for headlamps. This is echoed by any serious vendor with possibly one exception (RHD and LHD):

https://www.justaddlightness.co.uk/cate ... -headlight

This exception is expensive, but the vendor is very helpful.

As I wish to be able to rally/race within a FIA context, I have opted for new Cibié 5 3/4" units (for 26R type lamps) with Philips uprated H4 (EC legal) bulbs. I have not yet tried this combination. (The Cibié units are very expensive in Britain, but good value in France if you have the patience to look (I bought mine from www.yakarouler.com)).

I also plan to mount PIAA HID 140mm spot lamps for racing / rallying placed within the front air intake and mounted "cross-eyed". These are very effective as a supplementary source of light (I used to ahve them mounted on my MGB...behind the front grille!). These are not necessarily FIA acceptable, but scrutineers are more understanding if these are discreetly mounted.

For all of the other LED bulbs, I bought these from http://www.bettercarlighting.co.uk/index.php. A great deal of patience is needed on this website to find the right bulbs (for F & R indicators, brake lamps, side lights).

I'm happy to pass on the references if it would help but owner Gil Keane may remember my order as we had a good natter.

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PostPost by: prezoom » Mon Jul 09, 2018 3:52 pm

I had a similar problem with the thermal switch on my Plus2. What I found was, the spade connector on the output side of the switch was quite loose, thus causing a high resistance connection, which in turn caused the switch to operate. A healthy squeeze with pliers tightened the connector to the point that it was difficult to re-connect. No problems since. It was a first attempt solution. If there had been more room under the dash, I would have replaced the connector and the insulating cover, which was also severely heat damaged. As a replacement for the cover, I used a double layer of heat shrink material.
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PostPost by: elanfan1 » Mon Jul 09, 2018 4:44 pm

Might I suggest it would be a good idea to add the bulb pdf and other useful LED stuff to this threa£ in order to attemp5 to keep it one easily searchable thread?


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PostPost by: LotusEngineeringBuff » Tue Jul 10, 2018 9:08 am

You are right. I did not find this thread before writing my post. I will add more info to my sheet (like luminous values in Lumen, since Watts are not meaningful to compare filament lamps (i.e regular) with gas discharge lamps like Xenon or LEDs) and re-post where you suggest.
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PostPost by: denicholls2 » Tue Jul 10, 2018 4:30 pm

An important consideration for the bulbs used in turn signals and flashers is that the original flashers are mechanical (bimetallic strip). LED bulbs will not draw sufficient current to heat the strip and make the bulbs flash, so the flasher relays must be replaced with electronic versions (and these must not be current-sensing either, as many aftermarket items are.)

For the U.S., I doubt anyone will look close enough for compliance (an inspection here consists of seeing if the bulbs work and occasionally if they are aimed properly.) Lowering the current draw for the high-amperage items like headlamps is a good safety move and simpler than adding relays. Digging out the lamps is also a good opportunity to add or renew dielectric grease on the Prince of Darkness' connectors. The unobtainium indicator switches will also last longer without high current draw.
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PostPost by: bob_rich » Sat Jul 14, 2018 7:56 am


LED bulbs look interesting. Looking at the headlamp bulbs I would see if you could get a drawing of the overall size
the electronics that power the LED's seems to be housed in the alloy heatsink at the rear of the "bulb" I would check that the depth of this still permits it to fit ok in the pop up headlamp pod of the Elans and +2

also how is the electrical connection made to the LED bulb this may further increase the depth requirement

hope this helps best of luck

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