Your best bet is to:
1. Consult your owner's manual: This is the most reliable source. The manual should have a diagram of the fuse boxes and list what each fuse controls.
2. Check the fuse box under the hood: This usually contains higher-amperage fuses, but sometimes the radio fuse is here.
3. Check the fuse box inside the vehicle: This is often located under the dashboard, sometimes near the steering column, or in the center console (depending on your model). This is the more likely place to find the radio fuse.
4. Look for a fuse labeled "Radio," "Audio," "Power," or a similar description: The label might not be exactly "Radio," so look for anything related to the car's audio system.
5. If you can't find it, consider seeking professional help: A mechanic or auto electrician will have access to schematics and can quickly locate and replace the fuse.
Remember to turn off the ignition before working with fuses to prevent electrical shocks.