Battery isolation and immobolise, Help!

I have just installed a battery isolation switch for track work etc.
The battery disconnect part is all done and works fine.
It also includes a separate switch at the base of the unit to disconnect the ignition.
The point being that once the car is running and using the alternator, you can disconnect the battery but the car will still run.
All the work is done, but i can't work out which wire/fuse/relay to disconnect with this separate switch.
I can remove the fuses one by one and the relays one by one but the car still runs.
I have studied the schematic in depth but can't definatively pinpoint where I should break a circuit.
Seems strange that the coils are apparently unfused but never the less.
Anyone done this before?


Steve.

 

Martin, thanks for that.
I had gone through the different connections to the ignition switch, 30, 15, 75 and 50 etc to try and work out their pathways.
15 seems to run to the fuse block and then off to instruments and reversing light etc.
Does it have another destination and hence will stop the engine?
Any idea what these numbers mean?
Also, do you have an explanation re the surge when the battery is disconnected while running?
I do understand electrics fairly well and the islotaion switch does come with a resistor to connect to stop this occurence.
My only paranoia now is that due to an existing isolation switch in the front compartment and hence following on from its installation, my new isolation breaks the minus connection from battery to the ground of the vehice.
My theory was that this is the same as breaking the positive in a dc powered vehicle and a little easier, but how does that effect this instal of this resistor.

Steve.

 

Martin, after much grovelling undernetah the dash I can confirm that wire #15 (azzure) is the right one.
Thanks