Why is My Fuel Gauge Not Working?

The fuel gauge is one of those parts of our cars that isn’t “essential” to drive, however driving with a faulty or broken one can lead to stressful or dangerous situations. In this article, we’ll discuss why your fuel gauge may be experiencing issues and what to do next!

Fuel gauge
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How Does a Gas Gauge Work?

Before diving into what issues might prevent your gauge from reading properly, it’s important to understand how it works and reads the fuel level in your car. 

In most vehicles, the fuel gauge consists of two different parts: the sending unit and the indicator. 

The sending unit is responsible for reading the fuel level and is generally made up of three certain components. The float is a buoyant piece that does exactly what you would expect, float on the top of the fuel. This piece is attached to the arm, a thin metal rod connecting the float to a variable resistor. 

Using a combination of this float and variable resistor allows your vehicle to read the current level of fuel based on changes caused by the changes in electrical charge through the resistor. These changes are translated into the fuel level displayed on the indicator. 

Why is My Fuel Gauge Not Displaying Correctly?

There are a few possible reasons your fuel gauge may not be displaying the proper level, including:

Detached/Stuck Float

Reading your fuel level all starts with the float, so if yours somehow becomes detached from the arm, the reading on your gauge will be incorrect. When this occurs, your indicator will most likely be reading empty despite fuel being present.

A similar issue can occur if the float and arm become stuck. In some cases the float will be jolted back and forth due to the movement of the vehicle, leading to sporadic readings. 

Electrical or Variable Resistor Issues

The fuel indicator works almost entirely on electrical charges, which leads to a host of potential electrical gremlins that can disrupt the reading on your fuel gauge. These problems can range from a corroded wire to the variable resistor itself, and diagnostics are often tedious and in-depth. 

Blown Fuse

A blown fuse is another possible electrical issue, albeit a much easier one to diagnose. Luckily, you’ll easily be able to tell if the fuse is blown after pulling it out and inspecting it for a gap in the metal piece within the fuse. If this gap is present, the fuse is blown.

Cqdx, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

In some cases, however, a blown fuse might just be a symptom of a deeper electrical issue. If you replace a blown fuse and it blows again immediately, there could be a short elsewhere in the system.

Electrical System Diagnostics & Repair in Naperville

If you’re experiencing a faulty gas gauge, or any other system in your electrical system, trust the expert technicians at Becker Service Center in Naperville, Illinois for your diagnostics and repair! Our team has extensive experience working on all makes and models. Give us a call or schedule online today!