I want to put in a switch to cut the electrics from the barrel for anti theft reasons.
Can anyone tell me which wire on the barrel i need to put in an in line switch, also what wire to use as the switch will be hidden away from the barrel:wonder:
Cheers.

I've fitted a number of hidden imobiliser switches to various cars in the past. Fortunately only one has been tested in anger and it worked.
When you mount a switch give a lot of thought to it's location. You should be able to operate it when entering and leaving the drivers seat without anyone being aware of it. People may be watching from outside the car and passengers may let your secret good idea out. These things only work if no one knows about them.
The switch can either be hiden or camoflaged by marking it as foglight etc. A good way is to fit a standard switch in a blanked hole or use one that you don't need. How many of us actually dim the clock at night?
If you hide the switch don't put it where you have to stretch to reach it. That's a sure fire give away.
Don't get carried away with interupting the ignition switch wiring. That's the first place a determined thief will look. You can break into any critical wire. I've used the power to the ECU and the fuel pump supply before now. It depends what's convenient.
Make sure your wiring and all the components are of good quality. If your engine cuts at the wrong moment that big lorry you've just pulled out in front of could hit you instead of you accelerating away.

John