A fuel gauge that lies is dangerous — running out of fuel offshore is no joke. The fix is almost always the sender in the tank, not the gauge.
What to Check
1
Sender resistance test
Disconnect the sender wire at the tank and ohm it out empty-to-full. Out-of-spec readings = bad sender.
2
Float arm stuck
Old senders develop crud on the float arm or sticking floats. Pull the sender and inspect.
3
Wiring or ground
A bad ground from sender to gauge causes wild readings. Check continuity and clean the ground stud.
4
Gauge calibration
Some gauges (Faria, VDO) need calibration when you swap senders. Check spec.
When to Call Us
Sender replacement on most tanks takes 30–60 minutes. We bring senders for common Marine, Yamaha, and Mercury setups.