Final answer:
A warning light staying on after starting the vehicle usually means there's a problem that needs to be diagnosed and fixed. It is similar to a refrigerator light dimming when the motor starts, which is a sign of a voltage drop, but a car's warning light is an alert for potentially significant issues.
Step-by-step explanation:
When a warning light stays on after starting the vehicle, it indicates there is a potential issue with the vehicle that needs attention. Typically, the vehicle's onboard diagnostics system has detected a malfunction or an irregularity in one of the vehicle's operations or systems. The various warning lights on your vehicle's dashboard serve as indicators for different systems, such as engine problems, electrical issues, or safety concerns.
To connect it to an example with electricity, similar to when a refrigerator light dims due to the extra load on the circuit when the compressor turns on, lighting in a vehicle such as headlights or passenger compartment lights might momentarily dim when the engine starts. This phenomenon can occur due to a temporary drop in voltage caused by the high demand on the battery during engine start-up. However, persistent warning lights after the engine is running should not be ignored as they might signal more serious issues.