1957 Chevy 3100 Cluster Gauge Wiring

[jesse2135]

Hey guys i am finally wrapping up the harness install on my truck. Only thing is i got to the gauge hookup part and realized i cannot read or find terminal nomenclature for the ammeter or the fuel gauge. The ammeter has the terminals 2 with 2 male terminals on each side but i do not know which side is negative or positive to hookup the harness to. Also on the fuel gauge i do not know which post goes to what there are no labels. I know what each wire is for since i have the wiring diagram but i do not know what the terminal is. Any help would be greatly appreciated. Thanks guys!