* The security indicator light: This is usually a small light (often a key or a lock symbol) on the instrument panel. It will typically flash slowly when the alarm system is armed. The pattern might vary slightly depending on the exact system and whether the alarm is triggered or just armed.
* The horn: If the alarm is triggered (e.g., someone tries to break in), the horn will sound. This is the most obvious indication of the anti-theft system working.
In short, look for a small, possibly flashing light on your dashboard, likely near the other indicator lights. It won't be a big, obvious light, but a subtle indicator of the system's status. Consult your owner's manual for the specific location and behavior of your Charger's security indicator.