How to check your car's ignition switch: Ignition switch failures

Your car's ignition switch is responsible for distributing power from the 12V battery to all of the car's circuits.
Car ignition switch is also called ignition switch.
Basically there are 4 groups of circuits that the car's ignition switch manages:
1. Cigar lighter and auxiliary 12V sockets
2. Fuse and relay panel
3. Dashboard
4. Starter Ignition
Knowing this in advance we can then quickly, easily and reliably test the operation of the ignition switch.
With the help of a 12V lamp, like the one described in the following video:
• Cómo hacer una lámpara...
we can easily check if we have power in each of the positions of the Power Switch.
In battery position (marked as B on the ignition switch) we must find that one wire of the ignition switch has power: The test lamp lights up and that the other terminals do not have power.
Turning the ignition key to position I then energizes the cigarette lighter and auxiliary sockets.
With the ignition key in position II there must be power from the Instrument Panel and Fuse Panel cables.
In position III we must have 12V on the last cable every time we activate the ignition switch- like when we start the engine, that is, the starter motor should be activated.
In this simple way we will have tested the ignition switch of the car.
If one of the contacts fails we will have to change the ignition switch.