On 2001 ford expedition lights flicker when car turned on?

Flickering lights in a 2001 Ford Expedition when the car is turned on can indicate a problem with the electrical system, often related to a weak battery, failing alternator, or loose connections. It's advisable to check the battery's voltage and connections first, as corrosion or a loose terminal can cause inconsistent power. If the battery is fine, the alternator may be failing to provide adequate voltage, requiring further testing. Consulting a mechanic for a thorough diagnosis is recommended to avoid potential issues.