How to Troubleshoot a Fuel Pump Fuse
- 1). Check to make sure the ignition switch is in the "Off" position. Open the cover of the fuse block on the vehicle or appliance and locate the screws which secure it into the dash or the panel. Remove all of the mounting screws and pull the fuse block outward to expose the wires behind the fuse panel.
- 2). Locate the hot (red positive) and ground (black negative) wires connected to the socket tabs of the slot in which the fuel pump relay is inserted.
- 3). Turn on a multimeter and switch the measurement type switch to measure volts of direct current (Volts DC, or VDC). Set the meter to measure 12 volts.
- 4). Touch the metal tip of the red (positive) test probe of the multimeter to the metal tab of the fuel pump relay socket where the red (positive) wire is connected to it coming from the vehicle or appliance power system. Touch the metal tip of the black (negative) test probe of the multimeter to the metal tab of the fuel pump relay socket where the black (negative) wire is connected to it coming from the power source.
- 5). Turn on the ignition switch while continuing to hold the metal test probes on the metal connection tabs behind the fuel pump relay and look at the multimeter readout to see if the relay is putting out its rated voltage. If it doesn't, then the relay is most likely faulty and should be replaced with one of equal Voltage and Amperage rating.
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