Testing And Replacing A Fuse For A Car Radio Circuit

Posted on: 23 July 2015

If your car's radio system malfunctions, it can put a considerable damper on your everyday commute. If a malfunctioned auto radio has you driving in silence during your daily activities, then several root causes may be attributed to it. A blown fuse is a common reason behind the malfunctioning of car radios. This article explains how auto electricians identify a bad fuse and replace it in order to have your car stereo playing as normal.

Understanding the function of a fuse

Fuses, in automotive contexts, serve to ward off a wiring circuit in a car from drawing a lot of electricity and perhaps overheating, melting and causing a fire.

Identifying a bad fuse

A malfunctioned fuse is referred to as a blown fuse. In this scenario, the metal within the fuse burns and breaks resulting in an open circuit. Open circuitry basically discontinues the flow of electric voltage to the components of the circuit. To determine the state of an automotive fuse for a car radio circuit, auto electricians basically remove the fuse from its location and examine it. Normally, auto electricians will use diagnostic tools to test the integrity of fuses. Two diagnostic tools that are commonly used include:

  • Continuity meters
  • Test lights

Continuity Meters

They examine the integrity of a car stereo circuit. A malfunctioned fuse lacks solid integrity and in electrical contexts, represents an open circuit. Continuity meters generally use a straightforward noise test to ascertain whether a circuit features solid continuity. While testing the car radio circuitry using a continuity meter placed on the respective lead ends of the fuse, a resultant audible beep signifies a complete circuit while the lack of any sound signifies an open circuit or blown fuse.

Test Lights

A straightforward test light may also be used to examine the functionality of fuses. Typically, a test light features a pointed probe and clip on respective ends. In the middle section lies a light chamber. When the clip and probe are connected to a solid ground and a power source respectively, the bulb in the light chamber lights up when electric current is present. In order to use a test light to ascertain whether a fuse is defective or not, the circuitry must be powered. In the context of car stereos, the ignition ought to be switched on. Auto electricians usually tests the car radio fuse by connecting the clip to a hard ground while touching the probe to initially one end of the fuse inside the fuse casing and afterwards to the other end of the fuse. In both cases, light should shine on each side failure to which the fuse is considered bad.

Replacing a fuse

The electrician must ensure the replacement fuse corresponds with the amperage rating of the blown fuse and satisfies the car's requirements for fuse amperage. Typically, fuses are marked with a number that indicates their respective amperage load rating.

If you have specific questions about auto electric repairs, or if you believe your car has an electric failure, contact a mechanic with a shop like Drive-in Auto Electrics to learn more.