What To Do If Your Gas Needle Goes Up And Down?

What if you are driving your car to work and in the middle of nowhere your car stops running. You checked every possible fault that could happen but you are unable to find out any. You called a mechanic to get your car repaired and you find out your vehicle was out of fuel. But the gas gauge was not showing that. This is an unimaginable scenario you may face if your gas gauge is showing some issues.

So what can cause your gas gauge to damage and what you can do if your gas needle goes up and down? Read this article to understand this situation.

What Is A Gas Gauge?

The fuel gauge is a measuring instrument used to measure the amount of fuel left in your gas tank. The gas gauge is comprised of two separate units one of which is indicating unit and the other one is sensing unit. The latter one measures how much gas is present there in your tank and the previous one is attached to your dashboard, whose function is to indicate the level of gas in your fuel tank.

How Does A Gas Gauge Work?

The sending unit of a gas gauge is installed inside your fuel tank. This sending unit has a float that moves up and down with changing the level of fluid inside the tank, the float is connected with an arm that allows it to move according to its requirement. That arm is connected to a potentiometer, which varies its resistance according to the arm.

As soon as you turn on an ignition the electrical current is passed through the sending unit since the resistance of your potentiometer is varying according to the level of the fuel tank, and current flow is inversely proportional to the resistance, therefore more the resistance lesser the current flows. therefore the current flowing is tied directly to the level of gasoline in your tank.

The indicator unit whereas measures how much current is flowing through the sending unit at any given time and shows it on the dashboard in your car.

Why Would Your Gas Gauge Exhibit Failure?

Gause gauge is not very complex in its manufacturing as it only comprises two units. But every unit performs a specific function and malfunctioning of any unit can lead to failure of your gas gauge. Some of the common failure criteria are mentioned down below:

1. Malfunction In Your Sending Unit

Sending unit is always working whenever your car is running, due to its nature of constantly varying resistance, there is constant rubbing letting a lot of friction entering which can cause it to wear out after a time and can lead to broken connections, making the circuit open that can cause your indicator to show your car out of fuel all the time since your voltage feedback is obtained from a dead sending unit.

2. Circuitry Damage

Any damage in the circuit can cause disconnection in the whole gas gauge functioning. Any damage in sending unit will lead to no power to the indicator system or any fault in the indicator system might lead to wrong information in the dashboard. Since everything is connected any problem at any location in the whole circuit can lead to a damaged circuitry and a faulty gas gauge.

3. Gas Gauge Is Failing

This fault is less general but still, there is a slight possibility that this happens. When the internal circuit is damaged, the gas gauge will only function in one unit, such as between half and full or empty and half. If the internal circuits are shorted, the needle will sit at full or empty. But if the circuit is an open-circuit after damage, the gas gauge will remain positioned at empty and never move above it.

4. The Instrumentation Cluster Fails

This is the issue that does not happen that common Since the instruments that are manufactured now are fully integrated and if any of the pieces are damaged you will have to replace the whole cluster.

What Can You Do If The Gas Needle Goes Up And Down?

Now you know what are the common reasons that make your gas needle goes up and down, the real question arises that how you will be able to fix your gas gauge? So, the solution is lying inside what the problem is, depending upon what area is causing the problem you can find out the fixing procedure.

Such as if your sending unit is facing a problem diagnose the issue and replace the part which is damaged after replacing check whether your gas gauge is working efficiently now or not, if not try to check the connections again and again. If it works out the Voliah but if it doesn’t then you have to call an automobile expert who will take charge and repair your car’s gas gauge.

Similarly, any problem in the indicator system can be resolved but if your instrumentation cluster fails which is very uncommon but if it does experience failure then you cannot fix it yourself you must call a mechanic and get your cluster fixed.

Average Cost Of Replacing Sender In Your Gas Gauge

The most common issue is created in your sending unit only, and if you are not aware of any technical knowledge then you have to visit a mechanic. Now the question will arise what is the average cost to replace the sender in your gas gauge. So, depending upon the model and labor charges the repair cost will vary, but on average, the price for fuel gauge sender replacement is between $250 and $800 for parts and labor.


So now you know what is causing your gas needle to fluctuate or stop at a point, you also know what you can do if your gas needle goes up and down that is going out of control. So, get your car fixed and avoid a situation where you don’t know where your car will go out of fuel and will stop at any point on the road.

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