Fuses are simple electrical devices that are designed to stop electronic circuits from being overloaded. They come in many shapes, sizes, and designs, however, most automotive fuses use a strip of wire that will melt or break if the amount of current that is passing through it exceeds the amperage rating of the fuse. The fuse will blow in order to protect the circuit, wiring, and components from possible damage due to excessive current. When fuses blow or have any issues they can cause problems with functions and accessories of the vehicle. Usually a bad or blown fuse will produce a few symptoms that can alert the driver of a potential issue.
Accessories or functions lose power
One of the first symptoms of an issue with a fuse is loss of power to one or more of the vehicle’s functions or accessories. Fuses are installed in line of specific circuits in order to protect those circuits from potentially overloading. If those circuits do become overloaded, for any reason, the fuse will blow and cut off power to the circuit in order to protect it from the possibility of damage. If you notice that any of the vehicle’s functions or accessories, such as the radio, wipers, power windows or locks, etc, suddenly cease to function it may be related to a fuse.
Fuse is blown
Another, more direct symptom of a bad fuse is a blown fuse. If the fuse is bad, upon retrieval and inspection the wire inside of the fuse will broken, burnt, or otherwise disconnected. A blown fuse will have to be replaced with a new one in order to restore function to the circuit. A blown fuse should also be investigated to determine what caused the fuse to blow in the first place.
While most fuses should last a long time as long as the vehicle’s electrical system is operating correctly, over time electrical systems and components can develop issues that cause fuses to blow. If you find or suspect that one or more of your fuses is blown or may be having an issue, have the vehicle inspected and diagnosed by a professional technician, to determine if the fuse should be replaced, and if another problem may be present.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Fuse and was authored by Eduardo Ruelas.