Fuel Level
There are two usual symptoms to tell my boat fuel gauge is broken?
1. Fuel gauge does not read at all
Check the power with a multimeter at the gauge terminal. Test between the positive terminal on the fuel gauge and a good ground; the reading should be 12 volts. If it isn't, check the ignition circuit. If that reads 12 volts, turn off the ignition.
2. Fuel gauge stuck on empty/ on full/or with irregular readouts
One of the usual problems comes with the fuel sending unit, have it inspected by a professional technician to determine if you need to replace your fuel gauge sending unit.

B02-52-05 52mm Vintage Gauge Series - Fuel Level

B02-48-02 48mm Motorcycle Fuel Gauge
B02-T52FL-2 Fuel Level Gauge

R52FT-BN Dual Digital Gauge Fuel Level Water Temp

R52FT-BS Dual Digital Gauge Fuel Level Water Temp SILVER

R52FV-BN Dual Digital Gauge Fuel Level Voltmeter

R52FV-BS Dual Digital Gauge Fuel Level Voltmeter SILVER
B02-52-17 WIFI FUEL LEVEL GAUGE

