What is indicated by a very high or full-scale reading on an ammeter?

A very high or full-scale reading on an ammeter indicates an electrical issue, most commonly associated with the function of the voltage regulator. In a properly functioning system, an ammeter should show normal current flow corresponding to the operational needs of the aircraft’s electrical system. If the ammeter reads exceptionally high, it suggests that the voltage regulator is failing to effectively manage the charging process, allowing too much current to flow into the battery or electrical system.

This malfunction could result in overheating and damage to components, indicating that the regulator is not properly limiting the voltage output. Therefore, when faced with this kind of reading, it is essential to diagnose and address the issue related to the voltage regulator to avoid potential electrical system failure.

High readings on the ammeter do not directly indicate battery state, such as being fully charged or discharging, and they do not provide information about the function of the voltage regulator as operating correctly. Hence, recognizing a full-scale reading as indicative of a malfunction in the voltage regulator is crucial for maintaining the safety and reliability of the electrical system in aviation.