You may as well connect a loop of wire in parallel with the wire that goes to the ECM.
But this one I like.
![Image](http://img691.imageshack.us/img691/2655/neutral2.jpg)
putting switched 12v onto the neutral switch is a good idea. Then you must flip the switch, and press the button.
Oh oh, what if we had a switch with two pairs of contacts, so it closes two circuits at once? Tada!
One part of the switch closes 12V to the neutral switch, which in turn closes the relay, and the other signal is sent though the relay simultaneously.
What I'm trying to say is the "Switched 12v" and "Your Switch" are the same button, closed at the same time, when the button is pushed.