Trouble Shooting Fuel Gauge

[fbrewer]

We have two non-indicating fuel gauge. They both stopped working on the same flight.



Here is the back of the gauge:



We ran the multimeter accross the I and G terinals and could see 12 volts (we have a 12 volt system - RV-6)

To test the (S) sending terminal, we jumped from the I terminal to the S terminal -- the indicator did not indicate (no change and still showed empty)

We then jumped from the 12 volt battery to the S terminal -- still no indication on the gauge.

Have we tested this gauge properly and can assume both fuel gauges are inop?

[RV Jerry]

Assuming you have resistance type floats , ground sending unit wire and gauge should read full

[RV Jerry]

Also I terminal should have voltage

[DavidAhrens]

Odds of both gauges going bad at same time are very high! Please do not jump 12 volts to "S" terminal. "S' or Sender terminal is reading resistance from fuel tank senders which is normally 40-240 ohms.
You are welcome to call me for more information.
David @ 661 865-3529

[fbrewer]

Members,

I had Deene Ogden (Master of Aviation) help me trouble shoot my fuel gauges today.

Amazingly, it turned out that both gauges were bad -- what are the odds.

We know this, by having used the Multi-Meter to verify volts and resistance and then swapping out to new gauges.

The new gauges worked perfectly. Glad it was not a sender proble.

[jeffsvan]

We have used a decade resistance box to help troubleshoot fuel gauges.
The box llows you to dial in ohm readings to check the gauge. Also used it when calibration checking new digital units.