CDL General Knowledge TestDriving SafelyMedium
A commercial driver is preparing for a long trip and notices that the vehicle's alternator warning light illuminates intermittently. What does this indicate and what action should the driver take?
- AThe engine is overheating; the driver should check the coolant level.
- BThe headlights are too bright; the driver should dim them to conserve power.
- CThe battery is fully charged; no immediate action is needed.
- DThere is a problem with the vehicle's charging system; the driver should have it inspected.
Show answer & explanationAnswer & explanation
Correct answer: D. There is a problem with the vehicle's charging system; the driver should have it inspected.
The alternator warning light indicates an issue with the vehicle's charging system, meaning the alternator is not adequately charging the battery. This can lead to battery discharge and vehicle breakdown, requiring inspection and repair.
Why the other options are wrong
- A. The alternator light is for the charging system, not engine temperature.
- B. Headlight brightness is unrelated to the alternator warning light.
- C. An illuminated alternator light indicates a problem, not a fully charged battery.
Alternator Warning Light
An indicator light on the dashboard that illuminates when there is a problem with the vehicle's charging system, specifically the alternator.
- Indicates the alternator is not producing sufficient electrical power.
- Can lead to battery discharge and vehicle failure.
- Requires immediate attention from a mechanic.
Memory trick: Alternator light: your power's not right.