If a fuse is blown, you'll need to replace it with a new one of the same amperage. Blown fuses can be identified by their melted or broken filament.
Here are the steps on how to replace a blown fuse in a Mazda Bongo:
1. Turn off the engine and allow the vehicle to cool down.
2. Open the fuse box cover.
3. Locate the blown fuse.
4. Use a fuse puller to remove the blown fuse.
5. Insert a new fuse of the same amperage into the fuse socket.
6. Close the fuse box cover.
If you're still having trouble locating or replacing the fuse box in your Mazda Bongo, you can consult the vehicle's owner's manual for more information.