Malfunctioning Gas Gauge: Why it Happens and How to Fix It

Any number of things could go wrong with a car. While quite a lot of malfunctioning parts can cripple or even halt the car’s function altogether, there are some things that can stop working that won’t prevent the car from running, although they can be a serious inconvenience. Take the gas gauge for instance. This unsung hero of the dash lets people know about how much gas is in the tank. The following are some frequently asked questions about what happens when the gas gauge is not working.

Is the Gas Gauge Truly Necessary?

A malfunctioning gas gauge won’t keep you from operating the vehicle. However, if it is not working, then special care needs to be taken, as you won’t have an accurate reading of how much gas is in the vehicle’s tank at any given time. This can be downright catastrophic for someone out in a remote area. If you choose to keep running a vehicle without a working gas gauge, be extra diligent in keeping the tank full so as not to run out. If you have a good idea of what sort of mileage your car offers, you can use that to track how soon you may need to fill up the tank.

How Do These Gauges Work Anyway?

There are a couple of parts to a fuel gauge. Within the gas tank is a float. This float is connected to a rod, which in turn is connected to an electrical resistor. All of this is the sending unit. When the fuel level drops, the float drops. The electrical current is sent to the fuel gauge, which is what the driver sees in the dash. The current changes with the fuel level. Higher current means the tank is full, a lower current means the tank is reducing in level. This current acts on a heating coil near the gauge, which is in turn connected to a bimetallic strip. This is connected to the needle that the driver sees moving as the fuel level drops. There is also a voltage regulator that goes to the heating coil. Both the voltage regulator and resistor are connected to the battery via wiring that terminates in the battery cables.

What Should Be Checked First if the Fuel Gauge Isn’t Working Properly?

Most components in the car will not operate properly if there is a bad fuse. This is always the first step to take when determining an automotive problem, especially if the issue is in the dashboard. Either on the side of the dashboard just underneath or further underneath the dashboard is the fuse panel. Remove the cover and check the fuses. Replace any fuses that are blown. Check to see if this has resolved the problem. If it hasn’t, further investigation will be needed.

What Problems Can Cause the Gas Gauge to Work Improperly?

There are several problems that can cause a malfunction in the gauge. As mentioned, a fuse could be blown. The bimetallic strip attached to the gauge could be broken. Wiring connecting the gauge to the battery could be severed or otherwise damaged. The float could be bad, as well as the resistor. The voltage regulator can also be on the fritz.

How Can Fuel Gauges Be Fixed?

There are several ways to do this. Assuming that the fuses are fine, the dash would need to be taken apart and a look behind the panel will be necessary. The wiring as well as the strip and heating coil may need replacing. The voltage regulator can be replaced. Finally, the gas tank may need to be dropped and the float assembly removed and replaced. Kits can be purchased in virtually any auto parts store so the gauge can be replaced.

If the gas gauge is not working, this is not necessarily a cause for alarm. It does mean you won’t know how much fuel exactly is left in the car’s gas tank. Gas gauges are not entirely accurate to begin with, but one that is entirely non-operational leaves the driver in the dark as to how much gas is in the tank and whether it needs to be filled. Until the gauge can be fixed or replaced, it is advisable to not take long-distance trips and always err on the side of caution when it comes to filling up, until the problem has been resolved.