What is a Ground and why is it important?

April 5, 2019 by Coleman Thedinger

You’ve probably heard some life advice about how it’s important to stay grounded. When it comes to electronics, and your car audio, it’s very important to stay grounded.

If you’re researching what aground is because you’re thinking of cutting corners when it comes to grounding, let’s get this right out of the way: the ground wire is incredibly important, don’t take any shortcuts. The best-case scenario is you end up with an annoying hum that ruins your sound, worst case scenario is a fire. It’s serious business.

With that out of the way, let’s dig in and talk about what a ground is for, how it works, and how to fix ground loop.

What is a Ground?

This can be confusing, because ground can mean different things in different contexts. When it comes to your car’s electronics, the ground is a little bit different than when we’re talking about the electricity in your house.

The main difference is that your car is grounded to the chassis, rather than the earth. There are rubber tires in between your car and the earth, so no current is passing through there. In your car, the chassis is used as the ground, rather than using the literal ground.

Why the Chassis?

In your car, there are plenty of parts and accessories that need to be grounded. If vehicles didn’t use the chassis as the ground, it would be necessary to run twice as many wires throughout the vehicle. You would need the hot wire, and the negative. Instead, we’re able to just run the hot wire, and ground to the chassis to complete the circuit.

This makes things less expensive for vehicle makers, it makes it easier to install audio equipment, and it makes it less likely that your equipment will become damaged if there’s a short somewhere in your car.

Why It Matters

Many electrical issues in a car can be traced back to a bad ground, so this is not something to overlook. A problem with your ground wiring can cause your amp to shut off, it can shorten the life of your equipment or outright fry it, and it can even start a fire.

When your car’s electrical system was designed, they chose the correct gauge of wires for the stock electronics to use. When you add amplifiers and other aftermarket gear, it puts a heavier load on your car’s electrical system, so you’ve got to make changes to accommodate that.

The most popular modification that you can do yourself in just a few minutes is called the Big 3 Upgrade. This upgrade involves replacing three stock wires with lower gauge (thicker) ones to provide a better path. Since you’re putting a greater demand on the electrical system, this helps carry the load.

What is a Ground Loop?

A ground loop can cause all sorts of nasty noises to spew out of your stereo, and it’s not always an easy-fix, either. This happens when you have ground wires going to locations that don’t have the same ground potential as each other. This leaves some extra current, which turns into noise. If you have ground wires connecting to different parts of your vehicle, the main fix is to get them grounded to the same part of your chassis. If you didn’t properly sand off any paint before connecting one of your ground wires to the chassis, that could also be causing this problem.