By the title neither my fuel gauge and voltage gauge are not providing the values that boost confidence. The voltage gauge reads 16 volts with the red light lit both when running or lights on only. Car runs fine. Is this temporary as something gets too hot and wears out over time? I checked the voltage to the orange to black connections across the gauge and it showed the ~12V (engine off). The gauge shows 16V with engine off as well. With that I feel the gauge might need adjustment or replaced? Can they be rebuilt? The fuel gauge reads empty with the green light lit. The sending unit is brand new. I read in a different thread to test each connection on the sending unit by touching the leads to ground. The left, I believe the blue/yellow, killed the gauge to reading full I believe. The red/black connection to ground turned the light off. Zero resistant through the sending unit resister sounds like it should read full. Mine reads empty at all times. Before replacing the sending unit it read the same with a few flickers as you drove. I don't have any miles on the new unit to see. The old one's resister sounded like a box of rust. When the particles aligned I would get a reading, some reading at least. Both gauge's needles move when rotation the whole gauge cluster.