Warning lights
Warning lights are contraptions on a car's dashboard that indicate that something is happening, though not how much of it is happening. That would be a gauge. Warning lights such as those in the illustration communicate without using language, as one cannot be certain which language the driver can read, if any.
Warning lights are colloquially called idiot lights. This is either because the driver is an idiot, or because the light is idiotic, or it could be the people in government offices who decide the icon on each warning light.
Origins[edit]
In the days of steam driven cars there were no warning lights. You didn't have a dashboard either. Just a series of knobs and pulleys. You knew something was wrong if the engine exploded and you woke up either in a ditch or hospital.
Things were slighly improved in the analogue age; you now got a dashboard and messages printed below to tell you what a knob was doing to your car. It was only when batteries became heavy-duty that warning lights started to be used. People still ignored them all the same, so it would take the next generation to heed the pretty red and yellow lights they could see. Some time later, blue was added to show if you had just driven through an ice tornado and were about to freeze to death.