Just to make life a bit more interesting, most Bosch alternators are internally regulated, and will continue to charge unless you disconnect the main power feed, which will have unpleasant effects on the alternator diodes. I have hooked my kill into the trigger circuit on the main efi relay (Dodge calls it the ASD relay), which on my Neon kills alternator field, ignition and injector pulse. The advantage to using a low amperage circuit like a relay trigger wire is there is no chance of burning up the kill switch. The disadvantage, as I discovered when I installed an unknown used kill switch, is that not only does the car quit charging if there is a problem, the injectors and ignition quit too. Post up the wiring diagram of your cars injection relay, and I'll show ya which wire to cut.