Bad Fuel Sending Unit?

[jaybodine59]

Ok guys and gals,
Help here. My fuel gauge only reads 1/4 when full and then when level comes down less than that it appears to work. I changed out the sending unit with a repro and no status change. I jumped a ground to the connection behind the tag leading to the gauge and it reads empty. I connect it back up 1/4 tank. I unhook it and it goes way past full. It appears my gauge works. I jumped the ground from the sending unit to the same ground the tail lights use and no change. This leads me to think the sending unit is junk!!!