Wiring a Start/Stop button

[Darrenkidney]

Hi!

my new (to me) S3 - a kit build from 1993 - has an engine start button on the dash with just two connectors - it cannot stop the engine. 

Anyone have a wiring diagram to change to a button with start and stop function?

I'm happy to remain with the key as security and don't want a fob. 

Thanks!

Darren. 

[Jonathan Kay]

Do you already have the factory wiring diagram for your Seven? If you'd like a copy please send me a Private Message with your email address and details of the Seven.

Then choose the button you want to use and post the details here.

Do you have a battery master switch?

Jonathan

PS: If you're bypassing the immobiliser you might want to tell your insurer.

[Darrenkidney]

Hi Jonathan,

thanks for your rapid response and the outlook of assistance!

Unfortunately I got no technical paperwork with the car. Here's what I know:

S3 kit, first registered in Holland in 1993, Vx 2.0l 16v

Would a serial number and/or few under dash photos help identify it more closely?

There is no external battery master switch, but just a twist isolation switch mounted directly on the battery terminal.

Immobiliser? Pretty sure I don't have one :-) Insurance for "special vehicles" here in Germany seems a  bit more relaxed!

The button I have in mind is the one linked below.

12 V Car Motor Start Stop Pressure Switch Universal Waterproof Ignition Starter https://www.amazon.de/dp/B07H3PJT2W/ref=cm_sw_r_sms_c_api_i_dsdIEb7YB2JHS

Very grateful for any help :-) My email address is in your PMs already.

Regards,

Darren  

 

[Jonathan Kay]

No need for any details of the Seven. We'll sort out the car's diagram by email.

...

The button. And that Amazon page has identification of the terminals and various wiring methods in the gallery of photos.

 

Jonathan

[SM25T]

Why not just turn the key to stop the engine ?

[SLR No.77]

The usual modification to a Caterham is to fit a "big red starter button" which is a momentary push two connection press button connected in place of the starter-position wiring to the ignition switch (there's info on how to fit one here: https://www.lotus7.club/guides/how-guides/wire-starter-button). The button you've linked to may do the same but nothing more other than illuminate dependent upon how you wire it, there's scant info about the actual activation wiring. As far as I can tell it all seems to relate to the LED, unless there's something obvious I'm missing.

Unfortunately wiring the button to act as start stop facility (as per most modern cars) is usually more complex and involves adding an electric module of some sort. There was a unit built and supplied by a club member some years ago called a CatStart which enabled the red starter button to turn ignition on/off and start/stop using just the just the button, they're no longer available but occasionally they come up second hand. It might be that Car Builder Solutions or such make something similar but you'd need to check. I have a CatStart unit fitted and they're a great mod.

Stu.