The WIF sensor is integral to the fuel filter housing, located on the starboard side of the engine.
a - On‑engine fuel filter
b - Connector for integral water‑in‑fuel sensor
NOTE: If a boat‑mounted water‑separating fuel filter with a water‑in‑fuel sensor is used, the sensor harness will be connected
to the boat‑mounted filter.
WIF Sensor Test
1. If the WIF warning horn activates, remove the fuel filter assembly from the engine and pour the contents into a clear
container. If no water is present, disconnect the WIF sensor harness and perform a continuity check between the two
sensor pins. There should be no continuity. If there is continuity, the sensor is defective and the fuel filter assembly must
be replaced.
a - WIF sensor pins
DMT 2004 Digital Multimeter 91‑892647A01
2. If the sensor is serviceable, perform a continuity check on the sensor harness between the sensor connector and the PCM.
Check for shorts to ground. Note that there is a splice in the ground circuit.
DMT 2004 Digital Multimeter
91‑892647A01
Sensors
Page 5A-44 © 2018 Mercury Marine 90-8M0146617 eng JULY 2018