Will Disconnecting Battery Reset Fuel Gauge? All Answered

Did you detect your fuel gauge was damaged and read incorrectly? How to fix it? Will disconnecting battery reset fuel gauge? You’re in the right post. We will tell you what the causes are and give you the correct answer. Let’s read on.

How does a fuel gauge connect to the battery

What Is a Fuel Gauge And How Does It Connect To The Battery?

A fuel gauge gives you information about the amount of fuel left in your car. The fuel gauge fuse and the ignition switch draw power from the battery to force the control box, helping the fuel gauge display the received signals.

These signals are digitized using the physical system and being programmed from the vehicle system. The electrical circuit connecting the fuel gauge and the battery is a system of wires directly linked to the car battery.

The input data is from a sensor installed in the fuel tank that detects the remaining fuel level in the tank and sends this signal to the meter to display it to the driver. This type of sensor is connected to the rheostat via a lever.

Will Disconnecting Battery Reset Fuel Gauge? 

Will Disconnecting Battery Reset Fuel Gauge

Yes, you can reset the fuel gauge by disconnecting the car battery. You should note that there is no electrical input from the resistor when the gasoline level in the reservoir is low, or it’s out of fuel.

This also indicates that the circuits linking the fuse and valves are obstructed when the power connection toward the circuit board is terminated.

These valves work in conjunction with the transmitting module and resistor. The fuel gauge will reset, and the windshield readings will drop to zero since the system is not functioning.

How to reset the fuel gauge? First, you need to unplug the power cord connected to the battery’s negative terminal. It will allow you to test other electrical components safely.

Next, determine where the fuel level sending unit is, often in the petrol tank. This unit must be removed from the car when the cables are disconnected.

After that, look for any evidence of damage in the connections, and replace any broken ones. Additionally, you need to look for any loose wires and tighten them.

Why Does The Fuel Gauge Go Wrong?

Reset the fuel gauge is easy

Reset the fuel gauge is easy

Rusted Fuel Sending Unit

The fuel sending unit is the part that helps measure and transmit the remaining fuel level in the vehicle to the dashboard. After a period of operation, it can wear and rust, causing the circuits to open.

This will lead to the incorrect oil level data transmitted to the dashboard. It means that even if your fuel tank is empty, half-full, or full, the fuel gauge needle will not change.

Broken Circuit 

Broken, worn, or loose wires can trigger the entire electrical system to short. This is the reason why the fuel gauge does not read the correct information due to the lack of voltage.

In addition, the ground connection is affected by surrounding objects, so the system is interrupted when reading information. Your fuel gauge will end up delivering the wrong information.

Broken Fuse

The fuse controls the entire operation of the fuel gauge. You can find it in the fuse box under the dashboard or under the hood. If you see it’s black or the metal wire is melted, it’s definitely burned.

It will result in the fuel gauge not working completely. You can check the fuse for damage with a test light or a multimeter.

Gas Gauge Failure

This is a rare occurrence, but it can still happen due to some short circuit. The sign for you to detect this is the fuel gauge needle remains at the full or empty line.

How To Fix A Faulty Fuel Gauge?

How to fix the bad fuel gauge

Fill Up The Gas Tank Before Disconnecting The Battery

One of the reasons the fuel gauge reads incorrectly is that the fuel tank is not full. When the fuel tank is empty and you disconnect the battery, the control system will not receive the fuel-loaded information, causing the needle to still point to 0.

The simplest solution is to fill up the gas tank before disconnecting the battery. You also need to ensure that parts like fuses and resistors are out of default mode. Please check the wiring and connections to ensure the fuel gauge is completely reset.

If you still don’t succeed, then the problem lies in the resistor and the sending component.

Tighten Loose Connections

The connections of the resistors are loose, causing the transmission of the signals to be erroneous. When you disconnect the power in this condition, the battery terminals will malfunction, and even when you reconnect the battery, the fuel gauge will still misbehave.

Besides, it will also make the voltage unstable, causing short circuits and damage. The signal will not be transmitted at this time.

If the resistor works for a long time, it can rust, wreaking havoc on the fuel pump.

The solution to this problem is to tighten loose connections and replace the resistor if it is heavily rusted. You can go to the auto repair shop to ask them to solve this problem.

Replacing The Sending Unit

The faulty sending unit will trigger the fuel gauge to fail. Usually, when this part is faulty and you disconnect the power, the fuel gauge will remain in zero status after reconnecting.

Replacing the sending unit is a wise choice. You can ask the mechanics to repair and replace it. After reconnecting the battery, you should see the fuel gauge working normally again.


How to Ground The Fuel Gauge Before Connecting The Battery Again?

Grounding the fuel gauge before reconnecting the battery is important to ensure the safety of you and those around you. Once you’ve determined what’s causing your fuel gauge’s malfunction, you can begin resetting the fuel gauge.

First, remove the screws from the float, open the cap, clean the inside, and then put them back in place.

You can further check the wiring and connect them properly. If you find the gauge has problems, it is best to replace it to avoid further damage later.

In case the fuel gauge is still not fully grounded, you can ask the mechanics at the auto repair shop.

How To Maintain a Fuel Gauge?

You should regularly check and maintain the vehicle’s internal components and electrical systems to make sure the fuel gauge and other parts are working properly.

Failures in the fuse system or wiring can increase the pressure, causing the information received by the fuel gauge to be incorrect. In this case, you need to check and clean the fuel tank. If any cracks or leaks are found, they must be repaired immediately.

Remember to wear gloves and goggles when inspecting any part of the engine to avoid burns from overheating. Read the vehicle manual and follow the steps. You can learn how your battery works in advance to detect if it’s malfunctioning.


Will disconnecting battery reset fuel gauge? Yes. Disconnecting the power is one of the common solutions for drivers when the fuel gauge malfunctions.

If you suddenly find your Lexus RX 350 fuel gauge not working, we hope you know how to fix it. Pay attention to filling up the gas tank before disconnecting the power, tightening loose connections, and replacing the broken sending unit to avoid the fuel gauge needle pointing to 0.

We hope you found this article useful. See you in the next ones.

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