How to Fix a Faulty Car Fuse. Fuses protect your car from electrical short circuits and power overloads that can damage equipment or start a fire. Often, a fuse will blow due to a momentary overload, and replacing the bad fuse as directed below will fix the problem (a car's horn or interior lights may cease to work, for example). If a fuse blows repeatedly, it indicates an electrical problem that will require a trip to your mechanic. Read more: www.ehow.com/video_112724_fix-...