Thread: trouble shooting a fuel gauge

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What is the rated voltage for the guage?

Most gauges require a voltage reducer.

Getting a different reading by adding a ground indicates your ground isn't making a good connection.

Originally Posted by firebird77clone

What is the rated voltage for the guage?

Most gauges require a voltage reducer.

Getting a different reading by adding a ground indicates your ground isn't making a good connection.

Many OEM gauges use a voltage reducer, but Don said he's got AutoMeter which take a 12V feed. Also, Pepi's right on that black wire - it's likely the chassis ground. My AutoMeter fuel level gauge has three connections, 1) switched 12V, 2) input from the sending unit and 3) dedicated ground. Likewise the sending unit has one lug connection for the output, assuming a grounded tank. With a poly tank or fiberglass car a sending unit ground completes the circuit.

I'm betting it's an AutoMeter standard gauge wanting 240-33 ohm input, but a 0-90 ohm sender.