headlights not illuminating - Elan Sprint

[Mrmci]

Hi chaps,

I'm new to the group, having picked up my Elan last weekend. I got it started up to go for a run tonight, the lights popped up but won't light up. My side lights are working and tail lights, the instruments light up including the high beam warning light but I've not got dipped or full beam.

I don't have a wiring diagram yet, I was wondering if anyone could help me with where to start and how the system works. I'm fairly sure it was all working last weekend. I'm wondering if a drive back in the rain could have caused a bad earth but I can't work out how it's all wired and where it's earthed.

Any help really appreciated,

Mark

[jcocking]

There is a wiring diagram in the Wiki:

https://lotuselan.net/wiki/Category:Electrical

[pharriso]

There is a wiring diagram in the Wiki:

https://lotuselan.net/wiki/Category:Electrical

The one in this thread https://lotuselan.net/forums/viewtopic.php?f=38&t=50455 is much easier to follow

[Mrmci]

Thanks very much all, any ideas on usual culprits or best place to start?

[richardcox_lotus]

Thanks very much all, any ideas on usual culprits or best place to start?

I would start with checking the microswitches on the side of the headlamp pods. There will be one on the engine side of the driver’s’ side pod (RHD vehicle). They are actually reused door courtesy light switches and are subject to rain and corrosion when used on the pod. If they stick, then the lights will not turn on. It’s there as a cutout for when the pods are retracted but the dash switch has been left on.

There may be a second one on the pax side pod, but that’s not always the case.

Let us know how you get on

Regards,
Richard

[JohnMorin]

How old are the the relays? I while ago I had a problem where every time I slowed down the lights went out, changing the relays cured the problem. Do the lights come on if you rev the engine, if they do then this could be the problem.

John

[alan.barker]

I suggest you unhook the Spring and lift Bonnet off.
You then have access to Wires going to Headlamps. Clean and replace all the Bullet Connections you can get to.
I cut the insulation on outside of bullet connection blocks. Then you can open the blocks with a scewdriver without pulling the bullets off the cables. Fit new female bullet connectors (buy a bulk packet 50+).
Dremel with rotary wire brush to clean male bullets.
Alan

[types26/36]

Before you get involved with the wiring and relays I suggest you do the simplest thing first.
There are two micro switches fitted, one on the left side h/l pod and one on the right side pod.
The left side is for the headlight flash system (if still fitted) but ignore this one.
The right side micro switch is for the headlight operation and the one to be checked.
With the headlights switched on via the rocker switch (ignore the vacuum pull switch) manually raise the right side pod and an audible “click” should be heard. This is the main headlight relay operating (it is being earthed via the pods micro switch) and the headlights should come on.
If the relay does not click in then check the right side micro switch is clean, working with its black earth wire connected and going to earth.
If the micro switch is earthing and the relay (situated on the left side just behind the radiator) does not click in then I would suggest you test the relay.
EDIT, This is assuming the car is a S4/Sprint as S3/2/1 cars have a different micro switch.

[Mrmci]

You are all stars, thankyou very much. I will test that microswitch and report back.

Photo is hugely helpful!

[Mrmci]

Right....I can confirm that it does appear to be a problem with the RHS microswitch. Doing a continuity check across it I never anything other than infinite resistance and if I short it out at the relay my lights come on.

Any suggestions on best place to source and any tips on refitting a new switch?

Thanks for the amazing help so far

[nmauduit]

theses switches are rather simple, an alloy tube, spring, some insulating gaskets : you may want to check if a bit of contact lube would and clean up would not get it back on... you could also by pass it in a pinch (they are a safety feature so that the headlight are not heating up while closed, but they are still controlled from the dash)

[types26/36]

There is not really much to go wrong with the switches, usually they just want cleaning to make contact or the wire connections are loose or broken.
You also have to make sure one end of the wire is connected to earth as the switch just passes an earth signal to the relay.
The switches are a car door light switch and can probably be found on ebay if necessary.

[Mrmci]

And fixed, took the microswitch out, gave it a good clean, moved the earthing wire from the back to the front face so that it sits under the scree head and we're golden.

I suspect that the other microswitch which apparently controls the flash is also playing up but I think my back has had enough for now. Not particularly easy to work on.

Thanks for all of your help.

[richardcox_lotus]

And fixed, took the microswitch out, gave it a good clean, moved the earthing wire from the back to the front face so that it sits under the scree head and we're golden.

I suspect that the other microswitch which apparently controls the flash is also playing up but I think my back has had enough for now. Not particularly easy to work on.

Thanks for all of your help.

Glad we could help.

Regards
Richard