Ammeter indicates Rate of Charging when Battery switch (shown here selected to Right Alternator) is switched to either alternator.

When Battery Switch is centered, Ammeter indicates Battery Discharge, and should be referred to when testing for Pitot Heat and Windshield Heat system integrity. It is believed that the windshield is heated over only a part of its surface at present.

Red indicator lights show when either one or other or both alternators are not charging and should be checked as part of the pre-flight checks and monitored carefully as part of en-route checks. The appearance of a red light may also coincide with a Low Voltage Warning which might suggest that the problem is with the battery rather than the Alternators. Either way, refer to the Checklist for the appropriate drills

Refer to Checklist for actions in event of alternator failure indications (which may not actually amount to an alternator failure) and for notes on how best to conserve power in this event.

In the event of an Engine failure, the Battery switch should be moved to point to the operative Engine, and the alternator charging rate monitored.