Dashboard lights turn off when I turn use headlights

ok dimmer is ON the pull out switch, this combination turns it off somehow, not sure if this is operator error or not~ my toyota had a separate "dimmer" so in the country one might dim the dash lights, you do not always want them of blinding strength~ re-examine the way that you are using the dimmer~

There is a knob by your headlights switch that controls the lights on your dash turn it up or down to you desired position and brightness of dash lights if turned all the way up it’ll also turn on all lights inside the vehicle

Dash lights in your car are bright for day tine driving so they overcome the daylight. At night, the dash lights dim so as to not produce a glare while you're driving at night. Here, you have a dimmer to control night lighting. You might have the dimmer turned down to its lowest setting, or turned off completely. Other possibility is if your car has a sensor that detects ambient light and turns on the headlights automatically in poor light conditions, it's defective, but if so, it probably wouldn't turn on the headlights either.