Hey guys! Just a bought a 1997 2500 12 Valve. My fuel gauge doesn't work. What could I do to get it working again?

I heard that it could be the Fuel sending unit or the actual gauge on the dash. But I don't know how to check if it's the the Fuel Gauge needle?

Plus I've looked online for the Fuel Sending Unit and I can't find it. Could one of you kind fellaws send me a link to the part if you happen to know where ones at??

Thanks fellaws!

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