which illuminates this warning light. It's easy to see if you've switched it off by accident by pressing the respective button on the dashboard, and it should also light up if there's a fault that has ...

Hambleton said: "The engine cooling warning light, resembling a thermometer over wavy lines, is one of the least recognised dashboard symbols but crucial for preventing serious engine damage.

Many dashboard indicator lights are self-explanatory, like the seat belt or low fuel warning lamps. Others, especially on modern cars, might be more confusing.