How can you tell if a relay fuse is bad?

To determine if a relay fuse is bad, first visually inspect the fuse for any signs of damage, such as a broken filament or discoloration. You can also use a multimeter to test for continuity; a functioning fuse will show a continuous circuit, while a bad fuse will not. Additionally, if electrical devices connected to the relay are not functioning, it may indicate a blown fuse. Always ensure the power is off before inspecting or testing fuses for safety.