What would NOT indicate that a charging system is undercharging?

The option that does not indicate that a charging system is undercharging is short light bulb life. While an undercharged system can lead to poor performance and various electrical issues, short life span of light bulbs is typically not a direct result of undercharging. Instead, it can be attributed to factors such as electrical surges, improper voltage regulation, or using the wrong type of bulb.

In contrast, slow cranking is a classic symptom of an undercharged battery, as insufficient voltage can result in the starter motor failing to turn the engine over quickly. Dim headlights also suggest an undercharging condition, since headlights draw power from the battery and may not shine bright enough if the battery is not receiving adequate charging. Similarly, a low ammeter indication would show that the alternator is not supplying sufficient current to recharge the battery, indicating a potential issue with the charging system.