If you decide to upgrade or modify your vehicle’s electronics, there are safety devices that are designed to interrupt the flow of electricity to prevent the risk of electrical hazards – these are called automotive fuses, fuse blocks, and circuit breakers. 

In this blog, we will discuss what these safety devices are, their different types, and how they operate through different mechanisms to help you choose which device suits you and your vehicle’s needs.

Automotive fuse & its different types

An automotive fuse is a relatively inexpensive piece of metal that bridges two cables or wires of a car electronics system together. It is an intentional weak link that melts and breaks when excessive current flows through the wire to prevent further damage to your vehicle.  Once broken, the fuse needs to be replaced with a new one to restore the connection from the circuit.

Automotive fuses have different types that you can use to connect your car’s audio system. These are: 

  • ANL & mini ANL (MANL) fuse – Used for high current applications when you’re adding an amplifier. Available in current ratings up to 300 amperes. 
4 Pack of 80 Amp Nickel-Plated MANL Fuse
  • Blade fuse – This fuse type is most commonly used in modern vehicles and is classified into 4 main categories: Micro, Mini (APM, ATM), Standard (APR, ATC, ATO), and Maxi (APX). Their current ratings range from 1 to 100 amperes. 
30 Amp Maxi Blade-Type Fuses (3-Pack)
  • Glass tube fuse – Commonly used in older cars, glass tube type fuses are mostly designated with the AG (automotive glass) suffix and are available in current ratings of 1 ampere to 30 amperes.
4 Pack of 60 Amp Nickel-Plated AGU Fuse

Fuse holder & fuse blocks 

To prevent a fuse from being exposed, they are placed in a fuse holder. Fuse holders will secure the cable running to and from the fuse, as well as allow the fuse to be properly connected. Fuses will ensure that your amplifier is not receiving too much power from the car’s electrical system. 

On the other hand, a fuse block contains multiple different fuse circuits that distribute power to your vehicle’s electrical systems (including your car audio) and ensures that one voltage overload in a circuit won’t affect the rest of the circuits. Fuse blocks are usually made from flame-resistant, insulating thermoplastic material. To find where the fuse block is, you need to locate your car’s interior fuse box. 

Automotive circuit breaker

Circuit breakers are similar to fuses in that they provide in-line protection against excessive current.  The main difference between a fuse and a circuit breaker is that circuit breakers don’t break, but resets when interrupting the excessive current flow to prevent damage.

To demonstrate how it works: on the top of most circuit breakers is a lever that can be moved.  When too much power goes through the breaker, it will snap and interrupt the current flow.  The user then simply moves the lever and will reset the circuit breaker to enjoy the music again.

There is no need to buy extra fuses or parts since everything is enclosed inside the case of the circuit breaker. If the breaker becomes damaged or fails, then it is time to replace it.

200 Amp Circuit Breaker

Fuse vs. Circuit Breaker: Which one should you use?

Both automotive fuses and circuit breakers serve the same purpose in keeping your electronics, particularly your car audio system, safe from power surges and overload. However, both have different usage depending on your setup and electric load capacity. 

Fuses offer circuit protection that is straightforward – they keep your system safe in a sacrificial way, making them much cheaper and easier to install than a circuit breaker. It is best to use in low-current circuits.  

On the other hand, a circuit breaker doesn’t require you to replace anything if a surge occurs as it resets the circuit – making it a good choice for handling high-current circuit systems such as a multiple amp setup.