No 12V Power Unless Hidden Switch Pressed.

This is probably a very easy answer and has probably already been answered, but I couldn't figure out which diagram to use looking through the relay diagrams section or couldn't find it with a search of the forums. I would like to be able to press a hidden momentary switch that enables 12V power while starting my car and stays latched until power is killed (ignition key is turned off), but doesn't pass 12V power if the button isn't pressed on startup. Which one of the diagrams should I use? Thanks.

Is it the "Momentary to Constant Output" one (with a switch added in to the 12V fused? https://www.the12volt.com/relays/special-relay-applications.asp#mtc Or is there a simpler way to do this? Thanks.

Depending on your amperage requirements you may need to use another relay to supply ignition power: My ex once told me I have a perfect face for radio.

Thanks for all of the help guys. This is a low amperage line that is just a signal for my EFI to turn on, then it gets full power directly from the battery. I want to use it as a theft deterrent. To help me understand how this is working, I have a couple of questions. From the Passive Starter Kill diagram, is the line I am using for my 12 volt "kill" just the two starter wires on 30 and 87 if the first relay (it breaks continuity for my 12 volt power on signal until the button is pushed)? One wire into the relay and the other out to my EFI? geepherder: What is the reason for using the diode? I'm trying to see the flow of electricity. Thanks for educating me.

After looking at the diagram again, the diode is optional. It was there to prevent the starter wire from powering the output directly, but since it would only be momentary, it's not critical.My ex once told me I have a perfect face for radio.

Awesome, thanks. That looks pretty simple.