I'm having a similar problem and also posted on SB but i'll add to this..
I tested the connections between the gauge and float and it shows continuity.
I have a new float to install, and to test the gauge.
I also have a new gauge from bowtie bits to replace the original gauge.
I took out the old gauge and moved the indicator (that was pinned past full) to it's unpowered "rest" position.
When hooked to the float unit for testing, neither the new or old gauge will go above "empty". I did a bench test by supplying 12v to power side of the the gauge and continued to the float unit and grounded the float unit. When power is supplied to the gauge, it only jumps to Empty and stops. When the float is moved up or down, the gauge just stays on empty.
The original gauge number is 5643018 and the new gauge number is 564454. They look identical but could this be the problem? Could the both gauges be bad also?
Any help would be greatly appreciated.
