Its not even at 0.... When I was driving i noticed it was below the 0 line. Was a quart low ( pan gasket needs replaced). Filled and still showing nothing. All wiring clean and tight.

Is there a quick way to test it?

 

try shorting the wire to ground. should peg the gauge. if it does, it's the sender.
if not, either the wring to the gauge or gauge itself is bad.

is the sender installed in the factory location?