Ok folks....I realize that this has been gone over a million times, but here goes my turn. 63 Chevy truck, 12 volt system. Brand new wiring throughout whole truck, new fuel tank sending unit, guage just rebult by bowtie bits. Have good power and grounds...have plenty of fuel (1st thing I checked) and guage will only read 1/4 full. Everything is for 0-30 ohms. Help please.