What is the potential cause of a vehicle charging 16 volts?

A vehicle charging at 16 volts indicates a problem within the charging system, specifically related to the voltage regulation. The voltage regulator is responsible for maintaining a steady voltage output from the alternator to ensure that the vehicle's electrical system operates correctly. If the voltage regulator is faulty, it may allow the alternator to overcharge the battery, leading to excessive voltage levels like 16 volts, which can damage battery cells and other electrical components.

In contrast, while a bad battery could cause issues in the electrical system, it typically would not lead to such a high charging voltage. A faulty alternator, although it can contribute to charging issues, generally does not inherently produce a voltage that exceeds normal levels unless combined with a faulty voltage regulator. Loose connections can cause voltage drops and intermittent charging problems but would not singularly result in an over-voltage condition. Therefore, the voltage regulator’s failure is a direct cause of the excessive charge voltage in this scenario.