Push start/stop button

Basically what I want to do is to install a push start button into my celica. However I don't want any key use or anything at all. So when the button is pushed it needs to turn on all circuits and crank the engine. I also want to use the same puish to make button to turn off the car. I am fairly new to relays but have come up with this diagram below. Could someone have a look at it to see if they think this would work. Cheers

That looks correct to me, however you will need to confirm the number of ignition wires and accessory wires and modify the diagram accordingly, I would also suggest two things, one is that you add in a relay to five wire the wire comming off the switch so when you arm the alarm it will make the button not function. Second is that when you do this just tap the wires and dont actually seperate any of them that way you can still use the key if something fails. I dunno though, if I was someone who was not comfortable with relays, this would definatly not be my first project. But good luck to ya and I hope it works out. If you have more questions feel free to ask.double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

Cheers. I am leaving the ignition barrel connected for backup as you say. Also the alarm will activate switch, just couldn't be bothered to draw more wires on above diagram!! I have used relays before, but not just on such a scale and i ain't 2 bad at a liitle bit of wiring and soldering, my first bit of car electronics was to fit a Clifford AvantGuard 5 to my Celica, and it all works!! Once again cheers