I was just wondering why you'd need a relay for any type of kill switch system. Let's say I wanted to do one for my fuel pump, couldn't I just splice the wire somewhere, connect the toggle switch, extend the wiring, and relocate it somewhere hidden nicely???

 

You don't need a relay. It depends if you are going to have the alarm control your kill switch if you need a relay. Use the main relay as your kill switch. Grab a one amp switch and cut and splice the switch between the cut to control the main relay.

or

If you want to use your alarm. Grab a bosh or a good quality relay. Cut the ground to the main relay. Its allways black. One end of the cut ground goes to 30 and the other end of the cut ground goes to 87a. 85 will go to the ground while armed of your alarm. Or what ever ground signal that you will use to trigger the relay. 86 can go to the ignition input of the main relay. This will show 12 volts when the key is in the run postion. Unplug the main relay when testing for this wire. Or you can tag 86 to any true igniton source. Its up to how you are installing this and installer choice.

 

What if I just use the first idea but then eventually get an alarm..it would still work perfectly fine right???