1. Open the driver's side door and locate the fuse box cover on the left side of the dashboard.
2. Remove the fuse box cover by carefully prying it open.
3. Consult the fuse diagram labeled inside the fuse box cover to identify the fuse responsible for the radio.
The radio fuse may be labeled as "RADIO" or "AUDIO" in the diagram.
4. Once you have identified the radio fuse, use a fuse puller or small needle-nose pliers to remove the fuse from its slot.
5. Inspect the fuse to see if it is blown. If the fuse is blown, it will have a broken filament or appear melted.
6. If the fuse is blown, replace it with a new fuse of the same amperage rating. Do not use a fuse with a higher amperage rating, as this could damage the electrical system.
7. Reinstall the fuse box cover and close the driver's side door.
By replacing the blown fuse, you should be able to restore power to the radio in your Suzuki XL7 2002. If the radio still doesn't work, there may be other issues with the radio or the electrical system of your vehicle that require further diagnosis by a qualified mechanic or automotive electrician.