Why Would a Car Amp Blow Fuses?

Updated February 21, 2017

A blown fuse indicates that the circuit has a demand for more amperage than the circuit has the capability to handle safely without a possibility of melting wires or fire. The amperage demand of a particular item being operated will determine the size of the necessary wire. The smaller the diameter of a wire, the more resistance to amperage, differing only slightly by the material used in the core windings.


Always use a wire slightly higher than the amperage that it is intended to handle. An 18-gauge wire should be used for 10 amps or fewer. A 16-gauge wire should be used for no more than 15 amps, and a 14-gauge for 25 amps. Anything that uses 25 to 40 amps on a continuous basis should use 10-gauge wire. It is also important to point out that the longer the wire, the more resistance will be incurred. Wires should always be just the right length and with just enough slack for movement. This will reduce the resistance and improve performance.

Handling Amperage Loads

It is not uncommon to see much larger amperage demands in audio systems. Stereo suppliers have much larger wires with exotic metal cores to accommodate these needs. Always read the package for the maximum amperage loads, and add 25 percent for safety in the case of a loose wire or short. Always use a good grade of connectors. Bad connectors, loose wires and shorts will blow car amp fuses.

Power Supply

Alternators are designed for a 40 percent continuous duty-cycle and a flash amperage for a very short period. An alternator that is rated at 80 amps is only able to put out 32 amps continuously without heating up and damaging itself. It can flash to 80 amps for a short period when something is turned on. Always make sure to have an alternator that is large enough to accommodate the increased load without getting too hot.

Highest Db With the Lowest Distortion

The best sounding systems and highest Db are not the largest systems with multiple woofers of gigantic size. The system does not need to be very expensive, just have matched components and the proper wiring, connections and location of speakers. Face the woofers for best sound reflection. Finally, choosing the right speakers with the same ohms, wattage and highest distortion levels as listed on the speakers. The mid-range speakers in the front and rear should be matched evenly if they're from different manufacturers. The front tweeters should always be on a crossover for control. Having a system with the wrong components that draw too much power will blow car amp fuses.

In-line fuses

When choosing a car amp, be sure to choose an amp and wiring that matches your system. Do not skimp on the wiring--if the amp application calls for inline fuses in the wiring, spend the additional money for high-end inline fuses. This will keep the amp from blowing fuses, especially if the amp puts out a lot of wattage.

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