Aircraft Alternator
Maintenance Manual
ES1031
24-30-01
Rev. B: 20 Apr. 2022
Page: 3-1
© 2022 - Hartzell Engine Technologies - All rights reserved
CHAPTER 3 - TROUBLESHOOTING
3.1 General
A. In the event of malfunction in electrical power, it should not be assumed to be an alternator fault before
employing proper troubleshooting procedures. The overall objective of trouble-shooting is to find the cause
of trouble and take corrective action to prevent a recurrence. Even perfectly operational alternators
cannot compensate for improper adjustments, corroded or worn parts, and improper installation or lack of
maintenance.
B. This section provides general troubleshooting procedures for the alternator assembly for unscheduled
maintenance and for possible fault detection prior to maintenance activity. It gives procedures to follow
to determine the best course of action prior to disassembly. Block type troubleshooting charts are also
provided. Upon determination of fault(s), refer to the TESTING (section 6) for applicable test procedure(s).
3.2 Procedure
WARNING
WHEN SERVICING, REPAIRING, OR OVERHAULING THE ALTERNATOR, GREAT
CARE AND CAUTION MUST BE TAKEN TO AVOID HAZARDOUS SITUATIONS. THE
ALTERNATOR WHEN MOUNTED ON AN AIRCRAFT OR ROTORCRAFT, PRESENT A
PHYSICAL HAZARD FROM PROPELLERS, ROTORS AND OTHER ROTATING DEVICES.
THE ALTERNATOR PRODUCES A HIGH ELECTRICAL CURRENT OUTPUT AND ALSO
PRESENTS AN ELECTRICAL SHOCK HAZARD, THAT CAN RESULT IN SERIOUS
INJURY IF PROCEDURES IN THIS MANUAL OR THE AIRCRAFT/ROTORCRAFT
SERVICE MANUALS ARE NOT FOLLOWED.
Note:
It is required to reference the aircraft or rotorcraft AFM or POH as well as the applicable service or
maintenance manual as required.
A. The Charts on the following pages represent six main areas of trouble in an alternator. Choose the applicable
symptom and follow the trouble shooting chart flow. Below each chart is a discussion of each point.
3.1. Low or No Output.
3.2. Battery is Discharged.
3.3. Battery is Overcharged.
3.4. Noisy in Operation (mechanical).
3.5. Noisy in Operation (electrical).
3.6. Ammeter or Lights Flicker.
