UpFix Electronics Repair News and Tech

Troubleshooting Faulty Fuel Gauges

Written by Steve Chryssos | May 30, 2018 4:00:00 AM
Fuel gauges are an extremely important part of instrument clusters. They allow drivers to know how much gasoline is in their tank, and therefore how far they can travel before having to refuel. You could easily end up stranded with an empty tank of gas if you have a faulty fuel gauge.

Fuel Gauge Components

The fuel gauge consists of two parts that are connected: the sending unit in the gasoline tank and the gauge on the instrument panel. Gauges commonly have issues that result in tank levels showing as empty or full, even when they are not. The overall workings of the fuel gauge are fairly simple and can be tested at home before opting to purchase an entirely new instrument cluster or gauge.

Testing for a Faulty Fuel Gauge

The easiest way to test for faulty electric gauges is to do a self-test with or without a scanner. The instrument cluster will show fault codes that can be defined by your service manual. Additionally, you should always check to make sure the fuse on the fuse panel is not blown, which is responsible for voltage. These can easily be replaced with a fuse that has the correct amperage rating. If neither of these tests works or are not an option, you can manually check the components of your fuel gauge. Before beginning, make sure that fuel levels are below the hole where the sender unit is mounted to the fuel tank (this can be tested with a dipstick). If fuel levels are too high, you could leak gasoline when removing the unit.

Manually Checking Fuel Gauge Components

The fuel gauge is composed of multiple pieces: wiring, the sender unit, or the gauge itself can be broken. Wiring is the easiest item, so test it first. The sender unit is connected to wiring that sends signals to the fuel gauge you see on the dash. It will be installed through the top or side of fuel tank walls.

Wiring

If you can access the sender unit without dropping your fuel tank, check the wiring that runs from it in addition to the wires behind your gauge meter. If wires are corroded, cut, or loose, you may simply need new wiring.

Sender Units

Sender units can be checked for broken floats and fuel lines, or bent float arms which all may lead to incorrect readings. Before removing a sender unit always disconnect battery leads; you will be working around gasoline and fumes which carry a high risk for igniting when exposed to battery sparks.

Gauge

If sender unit wiring appears to be in good condition but there are still inconsistent readings, a circuit tester can be connected from one lead on the sender to the terminal. If the tester shows that wiring has a connection, the fuel gauge itself may need to be replaced.

Contact Us

If it is likely your fuel gauge or instrument cluster needs to be repaired, contact UpFix. Our company specializes in a variety of module and cluster services. For more information email us or call 888-979-9343.