Fuel Gauge Not Working

Call it a gas gauge or a fuel gauge, this device represents the level of fuel which is present in the fuel tank of any vehicle. A fuel gauge is designed in two parts: an indicator and a sensing unit. What I am going to say here should be a common observation for any uninitiated person. In a car you must have noticed a unit on the dashboard that indicates the moderation of fuel. There is letter 'E' and letter 'F' spaced with markings, which means the fuel is either empty or full! That indication is usually presented by a fuel gauge needle which floats in the unit, right? Well, it is that needle which is connected to a potentiometer in the sensing unit.

When a vehicle runs out of fuel and faces an empty fuel tank, the needle float drops to the empty indicator showing the driver that the vehicle is very low on fuel. Some cars show a 'low fuel' yellow light to indicate that there is no fuel in the car. If you infer to the working of a fuel gauge, the process is pretty simple and fail-safe too! However, on some days, there can be odds to the whole system and an issue can arise regarding your fuel gauge not working properly in your vehicle. Since, the fuel gauge unit is an electric circuit, failures are sure to come around sometime later. So, how are we going to crack the deal and know what are the exact problems causing a failure? First, know the working of a fuel gauge unit.

Working of a Fuel Gauge System

As we have already discussed above that a fuel gauge unit has two parts; sensing unit and an indicator, the sensing unit has a floating needle and the indicating unit measures the current. Let's read their individual roles now.

Since a sensing unit has a needle float linked to a potentiometer, the moment, a car faces an empty fuel tank, the float slides and falls to the empty indicator, i.e. 'E'. The floating needle moves along the resistor and enhances the resistor's resistance value. If you happen to notice a low fuel light in the unit, this means the resistance is at a point lower than the usual.

In case of the indicator system, this unit is mounted on a dashboard and its basic function is to display and compute the total amount of electricity passing through the sending unit.

So, after inferring to the working of both these systems, what we learn is, when the fuel tank in the car is completely filled, there is maximum electric current in the unit and the needle points to the letter 'F' (indicating full tank). On the other hand, when the fuel tank in the car is empty, the electric current is the least making the needle point to the letter 'E' (indicating empty tank).

This was the general working of a fuel gauge unit in a car. Some people aren't usually aware of the fact, that there is a fuel level sensor situated inside a car that monitors the fuel level. It is a mechanical device which stores the vehicle's fuel in the gas tank. It is this little piece of information most people are generally oblivious about. Hence, the working of fuel gauge was needed to be explained to comprehend the relative problems, in case if you are facing one.

Possible Problems Why Fuel Gauge isn't Working

• Add a fuel injector cleaner to the fuel tank, there will be an indication of full tank. Drive the car for about a few miles and if the indicator still shows full, there is a problem with the fuel level assembly. Get it replaced or repaired.
• When the car starts, the fuel gauge float can fluctuate and jump from full mark to an empty mark, regardless of the amount of fuel present in the tank. The needle or float is faulty or botched up. Tap the unit with your hand or call in for a check!
• When the vehicle is put into a reverse gear and therefore, when the driver operates the gear selector, the fuel gauge needle deflects randomly, at times pointing to E or at times to F.
• One of another reason is when the vehicle shows the right or left signal indicator and blinks, on every blink if the needle moves up and down on the line of the unit. Also, when the directional light switches on or off, there will be a slight sound or change in pitch from the fuel pump. This is a common fuel pump problem any vehicle faces. All of this indicates you need to go to a mechanic and get your fuel gauge checked or replaced soon.
• The most obvious problem is due to the faulty fuses and connector wiring. There is usually a black or yellow wire securing the connector of the fuel tank. If they aren't grounded well or in case have lost connection, that will cause the fuel gauge unit to show inaccurate readings. Take the help of a mechanic to rewire them well.

After reading this write-up thoroughly, I guess now you will not have any reason to curse your fuel gauge. Every mechanical system is bound to face failures, so just keep a cool head and sort all your car problems peacefully.