This is the conventional numbering of the contacts of the wiring harness connector. Please note that the connector socket is asymmetrical (the reference point is the mounting protrusion).
To test the switch you will need an autotester.
1. Disconnect the wire from the "–" terminal of the battery.
2. Remove the steering column trim (see "Removal and installation steering column trims").
3. Disconnect the lock wiring harness connector from the vehicle's electrical system and pull the harness out from under the instrument panel to a convenient position.
4. Place the key in the lock in all three positions one by one and in each position of the key use an ohmmeter to check the resistance between the contacts of the block.
If the ignition switch contacts are fully functional, the resistance is zero.
If the contacts are faulty, the resistance is infinite.
If the contacts are burnt, the ohmmeter will show some resistance.
5. To check the backlight, apply a 12 V DC current to contacts "2" and "6" of the wiring harness connector. If the backlight does not light, it is faulty or there is a break in the electrical circuit.
(The text is taken from the online resource: www.VAZbook.ru)
6. If contacts "15", "30" and "50" of the lock are faulty, replace the contact group (see "Replacing the ignition switch contact group").