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What Is a Shortstop Circuit Breaker & How Does It Work?

Written by Edwin Jones / Fact checked by Andrew Wright

what is a shortstop circuit breaker

Do you own a car or any vehicle? Do you want additional protection for their electrical system? What is a shortstop circuit breaker, then?

If you have a vehicle, you need a shortstop circuit breaker. A shortstop circuit breaker has the same function as your home electrical circuit breaker but is designed to fit in smaller and tighter spaces. It is essential to have this shortstop breaker, especially if you have many electrical components, like light accessories, installed on your vehicle.

Read on to discover the three shortstop circuit breaker types and their specific functions.

Everything About Shortstop Circuit Breaker


A shortstop fuse, like the Bussman shortstop circuit breaker, is made to protect 12 or 24-volt electrical systems. Like any fuse, the shortstop circuit breaker will trip when the electrical load exceeds the thermal design of the breaker. However, since it’s a circuit breaker, you can simply reset it instead of installing a new one.

This makes the shortstop circuit breaker a better replacement for your fuses. Although it may have a higher initial purchase cost, you can reuse it if it trips, thus saving you from the cost and effort of buying and replacing fuses.

The ampere rating of a shortstop circuit breaker ranges from 5 to 50 amps. The 5-amp breaker is designed to work with low-power accessories, like LED lights. Meanwhile, the higher-rated short stop 12v 40a breakers can handle more powerful devices.

These breakers can be installed in any vehicle or in battery chargers that utilize 12 to 24 volts DC current.

However, you can also find shortstop circuit breakers with a higher rating. For example, RVs with higher electrical loads can utilize a shortstop circuit breaker 50 amp to 100 amps for 48-volt systems.

In addition, some brands offer some breaker models with waterproof protection. Furthermore, a shortstop breaker comes in three mounting styles: standard right angle, parallel, and without mounting bracket. You can choose whatever design you need to fit your specific vehicle.

What Are the Three Types of Shortstop Circuit Breakers


Aside from the three ways of mounting a shortstop breaker, there are three shortstop circuit breaker types. Although all three designs will protect your vehicle’s electrical system, they all have different resetting features.

Type I: Auto-Reset Circuit Breaker

The most commonly used shortstop circuit breaker is the auto-reset circuit breaker. It trips immediately when a short circuit occurs in the system or when it detects high temperatures that it cannot handle due to circuit overload. Once the breaker cools, it automatically resets, allowing you to use the particular circuit again.

However, this does not repair the underlying issue. The auto-reset breaker will continue tripping until power is cut or the problem is resolved. So if the breaker trips again once it has cooled down, you should have it checked as soon as possible.

Type II: Modified-Reset Circuit Breaker

When the modified circuit breaker trips, the power to the circuit that it protects will remain cut. It won’t automatically reset unless you remove the electrical source. Once the electrical current in the circuit ceases, the breaker will then reset.

This offers better protection since you can continuously use your vehicle even if one of your electrical systems has a problem. Simultaneously, it’s also more convenient to use since you don’t have to pop the hood to reset it.

Type III: Manual-Reset Circuit Breaker

As its name suggests, the manual reset circuit breaker needs physical intervention to reset. This type of breaker has a manual reset button that must be pressed when it trips. This is best for sensitive electrical systems, like head units or GPS receivers. That way, you cannot accidentally switch the system on until the issue has been resolved.

Shortstop circuit breakers are easy and simple to install. Nearly anyone with a wire stripper and wire terminal connectors can do a clean and professional job. Watch this video made by Wiring Products to see how you can do it on your own ride.


What is a shortstop circuit breaker? Now that you know how it functions, and how it’s easy to install, you could now add additional protection to your car’s electrical system. Not only that, it will also save you money and effort from buying replacement fuses in the future.

So, are you planning to install this in your vehicle? Or do you already have one installed? Share your experience with your car’s electricals below!

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