A Faulty Fuel Gauge Can Wreck Your Day

Imagine you are having the best day. Calm water, blue skies, fun with family and friends and then it comes to a screeching halt. You are forced to endure the maritime equivalent of a walk of shame … getting towed to shore because you ran out of gas. Unless you are completely unobservant, how can you possibly run out of fuel? It happens more often than you might think thanks to a faulty fuel gauge. Knowing how your boat’s fuel gauge works and how to test it can help you avoid an abrupt and embarrassing end to a great day.

What Exactly is the Fuel Gauge and how Does it Work?  

The fuel gauge, as its name indicates, is the instrument used to measure the amount of fuel in the tank. The sending unit inside the tank has a float that relays the amount of fuel to the gauge. The resistance (ohms) is what causes the float to move. When the float arm is down, the resistance in the circuit is essentially zero (indicating an empty fuel tank). When the arm rises, the resistance will also rise. The needle on your gauge is moved by this resistance and the level of fuel. 

Got Issues?

Your fuel gauge is only reliable if it is in good working condition. Some gauges may suddenly not work at all or may give incorrect readings. The latter can land you in a bad situation as you may falsely believe you have a full tank and plan your outing based on that. If you suspect your fuel gauge is not working properly, it is important to test it to see if the issue is the sender or the gauge. If you prefer to have a professional perform the test, Pensacola Shipyard has experienced on-site contractors available. These experts possess industry knowledge to handle fuel gauge problems and more.

Testing 1, 2, 3

If you are comfortable trouble shooting on your own. First, test the voltage of the sender. Start the ignition and see if the gauge is getting 12 volts. If there is no voltage, you probably have a bad ignition circuit.

If the sender is receiving power, the gauge’s input unit should be higher than the voltage at the sender. If the gauge has 12 volts, the issue is likely the sender, gauge or wiring. Next, using alligator clips and jumping wire, connect the sender terminal to the ground terminal. If the gauge does not read full, then it is bad and will need replacing. If it reads full, it should be fine and the problem is elsewhere.

Sometimes the floating arm may be moving correctly but the rheostat isn’t transmitting the accurate electrical current to the fuel gauge. The result?  Both the sender and gauge will need replacing.

Incorrect grounding as well as dirty or disconnected wires are another issue. Verify that the ground wire is grounded to either the negative on the battery or to a common ground. Check wires at the sending unit for corrosion and if needed, clean them. 

Pensacola Shipyard Solutions

Knowing how your boat’s fuel gauge operates is not something most owner’s focus on until there is a problem. Unfortunately, the problem can occur at an inopportune time … like when you are on the water. Keeping your fuel gauge and other systems in working order is critical to ensuring enjoyable and safe ventures. Fortunately, it is not a chore you have to navigate alone. Not only does Pensacola Shipyard have a new and convenient fueling station to gas up your vessel, we are also home to some of the area’s most skilled independent contractors. These on-site industry experts understand all aspects of fuel gauge systems and can provide the assurance that your fuel level is measuring accurately. 

Call Pensacola Shipyard today to discuss how we can help ensure boat ownership that is stress free and safe.