15 replies to this topic

[Benito_S6]

Hi Everyone, I have a 1986 Mayfair with three instrument dash. I’m looking at adding a kill switch and have read that it can be done through the coil and tachometer. Just want to be 100% sure before I start doing owt. Splice into White/Black wire from coil(36) going to tachometer(53), add a switch, earth it and that’s all? Also, what type of switch, and wire needs to be used please. I’ve attached a diagram I’ve drawn, wiring diagram from Haynes manual and credit to dklawson for the explanation.

Attached Files

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Edited by Benito_S6, 03 February 2019 - 11:30 PM.

[Curley]

Can i ask why? Is it to stop people steeling it?

 

FWIF when I was at college my mate had a Beetle & me the Mini and we both used to take the rotor arm out of the distributor if we would leave them somewhere sketchy. I doubt anyone today would even know what a rotor arm is let alone have one to replace to steel your car :)

[Benito_S6]

Yeah it is for security reasons. Seems like the easiest and most convenient way of preventing starting. Piece of mind and not doing any harm in adding one is it. Good idea about the rotor arm though. Would love to see a thief try and work that one out!

[nicklouse]

 where are you putting the switch? what you have shown will just turn the rev counter off.

[Magneto]

The white wire that goes to the coil - put your switch in there in series.

[Benito_S6]

I also wondered if it would just turn the Rev counter off. That’s why what I’ve read confused me and wanted to check. Thanks for your replies. However, looking at the following it seems like a kill switch can be added through the tach. Added a screenshot from a old thread.

Attached Files

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Edited by Benito_S6, 04 February 2019 - 08:40 PM.

[GraemeC]

where are you putting the switch? what you have shown will just turn the rev counter off.

No it won’t. If you earth out the -ve terminal on the coil it will stop the points creating a spark as there is an easier path to ground.
This can be done by tapping into the tacho wire as per the diagram.

[nicklouse]

 

where are you putting the switch? what you have shown will just turn the rev counter off.

No it won’t. If you earth out the -ve terminal on the coil it will stop the points creating a spark as there is an easier path to ground.
This can be done by tapping into the tacho wire as per the diagram.

 

it would with the original DWG it has been changed to work.

[Benito_S6]

where are you putting the switch? what you have shown will just turn the rev counter off.

No it won’t. If you earth out the -ve terminal on the coil it will stop the points creating a spark as there is an easier path to ground.
This can be done by tapping into the tacho wire as per the diagram.

Thanks for getting back to me. That was my understanding also, I haven’t changed the diagram but the diagram the one with blue boxes would infact work?

Edited by Benito_S6, 03 March 2019 - 10:20 PM.

[nicklouse]

 

 

where are you putting the switch? what you have shown will just turn the rev counter off.

No it won’t. If you earth out the -ve terminal on the coil it will stop the points creating a spark as there is an easier path to ground.
This can be done by tapping into the tacho wire as per the diagram.

Thanks for getting back to me. That was my understanding also, so the diagram that I did with the blue boxes would infact work?

 

your new diagram seem to be right with the switch earthing the coil out.

[Benito_S6]

Got another mini and looking at doing this again, searched up and my old post came up! So wanted up update that this worked an absolute treat!

[whistler]

I just put a battery master switch in the boot; in the earth line.

[Ethel]

The coil fires when the earth of the primary winding is broken causing its field to collapse. Providing an alternative earth, via the rev counter wire, will stop it firing until that earth is opened & the distributor regains control.

 

It's not a lot, but it might do enough to make an opportunist bottle it. 

[stuart bowes]

I'm going a slightly different route, I'll use a relay operated by secret switch

 

that will enable the ignition starter (on key or button, tbc) but when not pressed, you'll just sound the horn

 

something like this should do it https://cpc.farnell....BhoCmK8QAvD_BwE

 

so you have n/o for the starter ingition circuit (closes when triggered by the switch) and the n/c for the horn circuit (opens when switch used)

 

and obviously the horn will also continue to work in the normal way via the stalk button as normal

Edited by stuart bowes, 14 May 2025 - 04:45 PM.

[Steam]

A big ass steering wheel lock will deter most opportunists.