1. Turn off the radio and disconnect the power: Before working on any electrical components, ensure the radio is turned off and the vehicle's battery is disconnected.
2. Remove the radio faceplate: The faceplate is the removable front panel of the radio. Consult the vehicle's owner's manual or search online for specific instructions on removing the faceplate for your GMC model.
3. Locate the fuse holder: Once the faceplate is removed, you should see the radio's internal components. The fuse holder is typically a small plastic compartment or box that holds the fuses. It may be labeled "Fuse" or have a fuse symbol.
4. Check the fuses: Open the fuse holder and inspect the fuses inside. Look for any blown fuses, which will have a broken or melted filament. Replace any blown fuses with new ones of the same amperage rating.
If you're still having issues with your radio after replacing the internal fuse, there might be a problem with the radio itself or other components in the vehicle's electrical system. In this case, it's best to take the vehicle to a qualified auto electrician for further diagnosis and repairs.