Question

Newer vehicles have equipment warning lamps installed on the vehicle's instrument panel. Which of the following statements is correct?

1. Before the engine is started the lamps should all be illuminated when the ignition switch is first turned on.
2. No lamps should illuminate until the engine is running.
3. The lamps should never illuminate unless there is a malfunction.
4. The lamps will only illuminate if the head lamps are turned on.

Answer 1

Before starting the engine, all of the vehicle's equipment warning lamps should illuminate when the ignition is turned on, as a bulb check. Once the engine starts, they should go out unless a malfunction exists. The dimming of headlights is related to the battery's internal resistance.

Step-by-step explanation:

The equipment warning lamps on a vehicle's panel have specific behaviors when you start the car. The correct statement regarding these lamps is: Before the engine is started, the lamps should all be illuminated when the ignition switch is first turned on. This is a check to ensure that all the bulbs are working. Once the engine starts, if everything is functioning properly, they should go out. If any lamp stays illuminated or turns on while driving, it indicates a malfunction in the associated system.

For example, when you're observing your car's headlights, they may dim momentarily as you start the engine. This is often due to the battery's internal resistance and the increased demand for electrical power to start the engine, not because the wires are superconductors. Superconductors would theoretically prevent this dimming because they would conduct electricity without resistance, but in practice, the battery's internal resistance still comes into play.