I assume you know that those lights are only intended to work while the headlights are on. There should be a dimmer control for the dash lights somewhere on the dashboard. It commonly used to be done by turning the knob of the headlight switch. But some newer cars now use a separate control. If that control is dimmed all the way, the dash lights will not be visible.
If you've made sure the dimmer control is not turned down, and the lights still don't work; the problem is usually either a defective dimmer control, or burned out bulbs.
I hope this helps!!!