CHEVROLET INSTRUMENT CLUSTER GAUGES FUEL LEVEL

My Gas Gauge Is Buried Below E. I Replaced Sending Unit But Don't Know Where To Go From Here. Any Help Is Appreciated. I Shared 2 Videos...

The Truck Starts But Does Within A Few Seconds And The Fuel Gauge Doesn’t Move Off Of E But Has Fuel.

Tried Two Different Gauges, Both Read Empty. The Newest Gauge Bounces When The Gas Moves Around. Am I Looking At A Bad Sending Unit?

My Gas Gauge Has Recently Started Acting Up. I Filled It Up And The Gauge Read Full One Minute Then Read Empty, Then Jumps Back To Full....

I Bought This Truck About A Year Ago And I Have Had To Make The Usual Repairs To Any Used Vehicle. I've Done Well Except Now My Gas...