How to Choose the Right Fuse

by David Lipscomb Google

    Fuses are essential, yet often misunderstood, components in any electronic device or mobile audio system. Selecting the right fuses for any application is essential in preventing fires, aiding in system enjoyment and long-term component reliability. Replacing fuses in your home stereo receiver or under the hood in a car stereo requires similar considerations for safe and reliable operation.

    Mobile Audio Systems

    Step 1

    Examine the primary power lead from the battery to the amplifier or main distribution block. Consult the reference below for a chart for matching wire gauge and fuse size. If you haven't installed power and ground wires yet, tally the amperage numbers for all devices in the system that will connect directly to the battery. This gives you the total amperage draw for the system, used to select not only the power and ground wires but the type and size of fuse used to protect that wire.

    Step 2

    Examine the product literature supplied by the manufacturer for amperage draw. Do not look at the fuse(s) mounted in each device, unless you know for certain they are of the correct value.

    Step 3

    Carefully examine the amperage and voltage rating on the fuse. Do not rely upon physical similarities to make a determination on which to use.

    Step 4

    Select the right fuse type for each application. ANL fuses are larger dual-hook designs, normally mounted within 18 inches of the vehicle battery under the hood and protecting the primary power line. AGC or glass fuses typically mount into distribution blocks mounted near multi-amplifier systems. ATC mini "wafer" fuses feature two tabs and slip into devices normally 30 amps or less. ATO or ATC maxi fuses capably protect in the 40 to 80 ampere range.

    Home Electronics Components

    Step 1

    Unplug the electronic device to prevent an accidental short circuit.

    Step 2

    Examine the back panel of the electronic device. Look for a small knob featuring a Phillips or standard screw head slot, labeled "FUSE" and typically with a value assigned. These fuse holders are commonly present in powered subwoofers, stereo and home theater receivers, stereo and multichannel amplifiers and other household devices.

    Step 3

    Rotate the cap with the appropriate screwdriver. Use caution as the threaded cap releases, since the fuse is often held tight with a small spring attached to the threaded cap. Additionally, the fuse may be broken from the failure, so watch out for glass pieces.

    Step 4

    Examine the silver sleeves at the ends of the fuse for the voltage and amperage values. These may also be printed on the fuse body, should the piece be a white-colored, high-voltage model.

    Step 5

    Replace the fuse with the identical model, ensuring the values match those printed on the back of the component.


    • You can always use a fuse rated lower than necessary, but never higher. If a short circuit occurs, the power leads will burn instead of blowing the fuse.


    • Never replace a low-voltage fuse with a high-voltage model. The amperage rating may look similar, but the voltage difference in the wrong application may be a fire hazard.

    Required Items

    • System or device amperage draw ratings
    • Manufacturer's product literature
    • Phillips or standard screwdriver

    About the Author

    David Lipscomb is a professional writer and public relations practitioner. Lipscomb brings more than a decade of experience in the consumer electronics and advertising industries. Lipscomb holds a degree in public relations from Webster University.

    Photo Credits

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