[Impulse]

You guys should use a spdt relay and a momentary switch to disable the ignition, fused off of the igntion at or near the ignition switch itself. Pin 86 to the momentary switch, then the switch to ground, cut the ignition wire open, pins 30 and 85 will go to the wire coming off your ignition tumbler itself, and pin 87a goes to the ignition wire going down towards the car. Doing it this way, the relay ign connections are already fused through the factory wiring, but you should put a fuse between the chassis ground the momentary switch. If the relay ever fails it will rest at normally closed, and you ignition will still be connected, plus there are not wires through the firewall. If you guys like I can give people tech support and wires colors for your vehicles because I have access to it since I am a 12 volt installer. Just shoot me a pm. Just my .02 cents.