The fuel pump fuse is normally blown out due to an electrical overload, short circuits, or wiring issues in the fuel system. However, the major cause of fuel pump fuse blowing is usually electrical overload on the fuel pump circuit. Most fuel pumps work on a certain amperage that normally ranges from 10 to 15 amps, with different models differing according to their type. The circuit will pop if the pump is overloaded-commonly because of a blocked fuel filter or increased demand on the motor, the circuit may draw more current than the fuse rating allows. Replacing a fuel filter every 20,000 to 30,000 miles helps prevent blockages from stressing the pump.
Short circuits within the wiring or connectors also can cause blown fuses. For instance, wires can be frayed and/or exposed to water, which allows them to become an unintended path for electricity, known as a ‘short circuit’. If a short circuit occurs there is a sudden surge of current through the fuse above that for which it was designed. This will cause the fuse to blow. The wiring of the fuel pump, especially in higher milage vehicles is checked on a regular basis to help avoid short circuits. The repair price for faulty wiring ranges from $50 to $100, but saves you from blowing fuses over and over.
A wearing or failing fuel pump motor will also blow a fuse. As fuel pumps wear and age, internal resistance increases with that process, making the motor work harder, drawing extra current. In this case, there’s a greater chance for it to draw higher levels of current and blow a fuse when the pump is reaching the end of its life-usually around 100,000 to 150,000 miles. Replacing a fuel pump, normally costing in the range of $300 to $500, would solve this problem if the wear in the motor was the root cause.
Another issue might be fuses that are rated incorrectly. A fuse rated below that specification in the Fuel Pump circuit could be prone to frequent blowing, especially under heavy demand during acceleration or on hills. The correct fuse rating should be used at all times according to rating specified in the vehicle’s manual.
The other factor is the fuel pump circuit’s grounding issues. A poor ground connection increases electrical resistance, and thus the pump has to draw more current in order for it to maintain normal operation. This excess current will overload the circuit and blow the fuse. Technicians will generally check the grounding points, making sure the connections are secure since a solid ground is critical to maintaining a stable fuel pump current.
These are the causes: worn fuel pump motors to proper fuse ratings, hence addressing them keeps off frequent fuse blowouts and gives the car better fuel delivery to keep the engine running smoothly.