Start a car without a key?

Basically I'm creating a finger print scanner that compares your fingerprint with the owner and if there's a match then your car starts, and you don't need a key.
I'm wondering how would I make the car start?
I won't specify a car but I will probably buy a cheap one for like 100 bucks since this is for a senior project.

So if you are answering based on a specific car base your answer of a cheap car.

Marie K2017-08-09T20:24:16Z

an older car may have a steering wheel interlock that needs a key so I hope you only need to make it start, not drive-able

River Euphrates2017-08-09T20:06:27Z

There are already a number of cars with remote and/or pushbutton start.

You would simply figure out how to wire a 12V fingerprint sensor into the system.

Alicia2017-08-09T19:48:33Z

You will need the schematics of the car you're putzing with...but when you turn the key to on, you're energizing the system. When you turn it to "Start", you're making momentary contact and closing the circuit to the starter.

So whatever you devise, it should be making momentary contact with the starter motor circuit and powering that to spin. But you'll need an easy way to put the car to the "on" position first or while you're doing that.

You might want to look at the ignition schematics for any car that has a push button starter or works on a remote starter key fob.

Anonymous2017-08-09T19:46:43Z

your scanner basically needs to control a relay .. you could make it all electronic, but it would probably be easiest to have the relay 'unlock' a push-button starter switch ..

jeff2017-08-09T19:44:47Z

I also might rent a cheap car

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