Courtesy light switch wiring

[Pastapesto]

Hi everyone

Happy new year to you all.

I need some help please!!!!!!!!!!!

I must be getting old & stupid but for the life of me, I cannot work out exactly how the courtesy light switch is wired & exactly how it is supposed to work & function properly.

My car is a very early S3 coupe which is very similar in a lot of ways to an S2 of the same period (wiring wise). It came off the road in around 1977/8 and hasn't been back since so I'm pretty damn sure it is how it was when it left the factory as far as the wiring on the back of the dash is concerned. The three toggle switches between the heater knob & choke are from left to right: Heater fan (one speed), Rhoestat (to adjust the brightness of the instrument lights) & the courtesy light switch. I have the courtesy light on the dash (which has a switch on the top) and one each side on the "B" pillars which do not have a switch.

The switch (courtesy light) is exactly the same as the Main Light Switch and was this from original (IMHO). Would anyone have a picture of exactly it is wired or a very good description of what goes where & from where each connection comes?

Obviously I have read & checked all of the wiring diagrams I can get my hands on & I have searched the archives with some success but I still cannot get the thing to work in any way I think it should and I want it to be as original as possible. I have been told that it is supposed to be a two position switch (off & on) but the dash was routed for this size switch & I'm positive it is how it was from the factory (ie. a three position switch). The wiring diagram(s) only really shows it as a two position switch and does not show which terminal to which wire very clearly. Has anyone else got an early Coupe that is the same or do I have an oddball car?

Can anyone help? A picture of the rear of the switch (wired) with a working description of what everything does in each position woulb be a godsend as I've already been up into the early hours twice scratching my head on this one.

I would really appreciate any help you could give me on this very perplexing problem - it's driving me mad

Thanks

Adam

[oldelanman]

Hi Adam,
This earlier post on the subject may be of interest if you haven't come across it already. It includes reference to a 3 position switch, albeit not an original fitment, but the same mod may have been done to your car.
elan-archive-f16/courtesy-lamps-t9443.html

[garyeanderson]

Hi Adam

I don't know how Lotus wired you early Coupe. My guess is there was a 2 position switch on the dash and it could turn on/off the over shoulder lamps independently. the parts book for the S1 s2 and Coupe lists two lamps for the coupe. Further more is lists 2 of each. To me that says the two switched units are on the B pillar and the un-switched units are on the dash and for the license plate lamp. what you have is 2 door switches a 2 position lamp switch on the dashboard and the lamp switches on each of the pillar lamps. So thats 4 single pole switches and 1 2 position switch to control 3 lamps. My dash photos arn't much help but they may help someone. Tough to do wiring over the internet, it's hard to do when it is right in front of you. Look though the parts book, if you don't have let me know and I'l see if I can get you a copy of it.

Gary

[TurbineHeli]

I'm about to undertake a complete rewiring of my S2 and the first order of business will be the elimination
of the chassis as a ground path. There will be a ground bus on either side of the engine compartment/cockpit
"firewall", linked together with a 5/15 brass stud and connected directly to the battery neg terminal. There will be a second ground bus in the boot to accommodate lights, fuel pump and anything else back there.
Seems to me that using a 45 year old chassis as a ground path together with wires and connectors of that age will lead to unnecessarily high resistance in the system.

AMA

[garyeanderson]

I'm about to undertake a complete rewiring of my S2 and the first order of business will be the elimination
of the chassis as a ground path. There will be a ground bus on either side of the engine compartment/cockpit
"firewall", linked together with a 5/15 brass stud and connected directly to the battery neg terminal. There will be a second ground bus in the boot to accommodate lights, fuel pump and anything else back there.
Seems to me that using a 45 year old chassis as a ground path together with wires and connectors of that age will lead to unnecessarily high resistance in the system.

AMA

I think you are over engineering the system, at the most I would add a copper earth path from the battery to the engine block but I have not found the need for that.

Gary

[Pastapesto]

Roger
Thank you for that reference to the earlier post, I have done the same with my setup and I am happy with how it is. If anyone knows exactly how it should be then please let me know.

Gary
Thank you for your input & help, as usual it was well set out & descriptive & helped me a lot. One thing I will add though is that I still think that it had the three position switch from new & to back this idea up, if you look in the parts list there is a diagram that shows the back of the dash (it looks like a S3 coupe to me) which has a drawing of the three position switch although there are no connections drawn in. I also still believe that it came with the switch on the top of the dash courtesy light.

The way I have it wired now is:

Switch in the up position = all three lights come on when you open the doors.

Switch in the middle position = "B" pillar lights come on -

Switch in the down position = nothing comes on including no door operated lights, handy if you want a door open for a while without draining the battery.

Dashtop light can be switched on at any time with the little switch it has because it has it's own live & earth system via the switched side, I hope that is understandable.

That is how I am going to leave it but if anyone knows better then please let me know .

Thank you all again.

Adam