Did you know that you could have an Anti-Theft Car Security System in your car by using only 2 relays, a switch (momentary contact), and a couple of wires? And it does not even require a control unit (ECU)?
Plus it does not matter whether your car is a BMW, Mercedes Benz, Audi, Toyota, Honda and others.
The system is very simple and it works this way – the car will NOT start unless you activate a switch that is hidden somewhere in the driver’s cockpit or wherever you choose to hide it.
There is also the option that you may disregard the switch. Instead of a switch, the activating device could be your brake lights, parking lights, radio accessories like power antennas and auxiliary power, the horn, and others. This means that your car will NOT start unless you turn ON either one of these accessories in your car, which ever you prefer. Of course the key must be in the ignition position.
The wiring diagram is provided below for those who are car enthusiast and DIY’s.
Just make sure to use a DIODE when you disregard the switch and the diagram is also provided below.
Or you could visit your nearest car accessory shop to have your car installed with this simple security system by a professional installer.
Reference, Diagram and Image source: the12Volt.com – Relay Diagrams, Google Images