Why won't my headlights come on?

if it is your running lights that wont come on, your emergency brake could be on, or the sensor may be reading that it is on. this defeats the running lights. you will know this is happening because the emergency brake light will be on. if this is the case, reach under the drivers side door and with the e-brake off, wiggle the e-brake cable back and forth. the running lights should come back on once the emergency brake cable is in the off position.