Definition
An 'idiot light' is an informal term for a warning light in a vehicle, typically a simplified symbol that illuminates to indicate a problem, like low oil pressure or a dead battery. It's called 'idiot light' because it's designed to be easily understood, even by someone with little mechanical knowledge. It’s a basic communication tool from your car. Often, it's a last-ditch effort of your car to get your attention before a breakdown.