Dash Lights, Carb, Radiator issues

Most common fault with illumination is the dimmer rheostat in the headlight switch ( turn the knob to adjust brightness ). There should be other lamps on this orange wire circuit ( radio dial at least ). If all are inop the rheostat is suspect. If some work some don't, the rheostat is good. And of course the inst' panel has to be chassis grounded for these lights to work. You mentioned working on gauges so I cant know if the panel is fully installed or dangling from the harness connectors.