The FreeEMS Box !

[Fred]

Added benefit of using a non-momentary switch = keeps the engine from starting should a low-life try to steal the car. If you install R7 in place of D1 then you could pretty safely run 2 wires out, externally mount the LED and the switch, and use a sensor ground wire to switch back against.

[masterkorp]

I key based switch would be nice.

[masterkorp]

About that key switch, while mumbling around on digi-key, i found this

C & K components Y100AA2C203NQ
With 3 positions, providing a way to somewhat securely getting the board in load mode, and since there are terminals that are complety isolated from each other, one position, can function as power cut off for the board, giving an extra basic security, the key comes out in any position, so you don't need to leave it there.

Datasheet

What do you guys think ?

[Fred]

Another nice idea! :-)