David,
Fuel gauges are generally Voltage agnostic and have a simple rheostat in the body of the sender. If the unit is new, I would investigate the wiring.
<p style=”text-align: left;”>If nothing has been done to either convert the clock to 12V or reduce the voltage to it, there is a grave danger of burning it out. If it has been made 12V compatible, and the fast running is not excessive, perhaps it simply needs adjustment.</p>
B….
Bernie