Lotus Elan

Need help with relays for Elan S3

PostPost by: tomjones20194 » Fri Nov 23, 2018 2:18 am

Hi -

I need help figuring out the part numbers and purpose for several relays on my Elan. In short, I suspect some of the relays are not original. For example one is a 4-pin type but has 3 wires connected and a jumper wire. The other two are located in the front left wheel well ahead of the radiator. They do not seem to do anything (I've disconnected them and the various systems still seem to work, eg, headlights.

I posted the full details here (bottom of page 3):

http://www.lotuselan.net/forums/lotus-elan-f19/elan-dhc-restoration-thread-warning-picture-heavy-t42859-30.html#p306600

Any help is greatly appreciated.

Thanks,
Tom
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PostPost by: billwill » Fri Nov 23, 2018 12:45 pm

The relays mounted on the inside of the left hand wheel arch in front of the radiator are the headlamp relays, one for main and one for dipped.

They are not wired as 'sensible' relays (which would relieve the headlight switch on the steering column from carrying the full headlamp current) instead they only serve to switch OFF the headlights when the headlight pods are DOWN. There is a microswitch on the right-hand headlight pod to do this.


I think there may be a third relay in that location, but off the top of my head I can't recall what it is for.
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PostPost by: tomjones20194 » Fri Nov 23, 2018 2:23 pm

Should there be a headlight relay underneath the dash? My Elan has one...

Looks like the previous owner bypassed the relays on the fender well too. My headlights work when they are in the closed position. Both high and low beams.
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PostPost by: types26/36 » Fri Nov 23, 2018 3:27 pm

I realise your car is an S3 but as discussed in other threads I have always found S3 cars to have the same wiring as S1/2 with the addition of electric windows. Anyway I do not want to start that discussion again but your car looks like it conforms with the S1/2 diagram to me.
1. Yes on the S1/2/ the main H/Light relay is under the dash originally mounted on the wiper wheel box screw and only had three terminals.
2.The under bonnet relay on the side is the flashing headlight relay.
3.The small round relay is the "headlight flasher unit"
I think the flashing headlight relay (under bonnet) is a Lucas 6RA/SRB111 which may have to be bridged because it has four terminals while originally I think the relay only had three terminals.
I have seen the relays with the bridge fitted from new.
I think I do have some more wiring diagrams detailing the "flashing h/l system,low beam and hi beam" circuits which I made up years ago when I was first rewiring mine, I'll have a look to see if I can find them.
Just to note, the S4 cars do not have a h/l relay under the dash, they are wired differently (much more complicated) with more relays.
In the UK the flashing h/l system is illegal (apparently :roll: ) and a lot of the cars have had the system disconnected or stopped working and people could not figure out how it fix them, whether it is illegal or not both my cars work and I never had a problem with the MOT (when we had to do it :lol: )
Attachments
headlight-flash.jpg and
old-relays-003-copy.jpg and
old-relays-004-copy.jpg and
old-relays-005-copy.jpg and
old-relays-006-copy.jpg and
s2-wireing-dia-copy.jpg and
s2-relays.jpg and
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PostPost by: tomjones20194 » Fri Nov 23, 2018 9:15 pm

Very helpful. Thanks guys. I had no idea there was a flashing feature for headlights. That is not something that we have on our cars in the US.

I traced the wiring and used a volt meter to figure out which are high and low beams. I also determined that my Elan has two micro switches as shown in the schematic above, but they are both disconnected. Looks like some parts are missing - is there an arm or rod that engages the micro switch when the lights are down?

I removed the two relays forward of the radiator and will just go with the one mounted under the dash. The wiring is simpler and cleaner and I do not plan to use the flasher feature.
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PostPost by: types26/36 » Fri Nov 23, 2018 9:23 pm

The micro switches are activated when the pod is raised by vacuum, there is a spring attached to the m/switch and this is connected to the pods large closing spring.
One m/switch activates the main headlight relay and the other m/switch activates the flashing relay.
The m/switches are nessarary to make sure the headlights are not on when the pod is closed.
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PostPost by: tomjones20194 » Fri Nov 23, 2018 9:33 pm

Ok thanks. The springs are missing on mine. I’ll reconnect the micro switch on the front right to re-enable the auto turn off feature when pods are closed.
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