AA5 pilot reported diverting to an alternate after noting an electrical system anomaly.

Attributes
ACN	1403333
Time
Date	201611
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Cheetah Tiger Traveler AA5 Series
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Vectors
Flight Plan	IFR
Component
Aircraft Component	Electrical Power
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Flight Instructor Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 13 Flight Crew Total 3928 Flight Crew Type 14
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

While under radar vectors for intercept of ILS; altitude warn light came on and system began to show an electrical discharge rather than a charge. To avoid any chance of serious electrical issues and to preserve battery power for landing (radio and flaps); we cancelled IFR with approach; turned to a heading of about 320 degrees; descended to 4500 MSL; turned off all electrical; and proceeded to [an alternate airport] (a location with maintenance facilities for aircraft type). Landed without further incident. Investigation on ground found a 'shorting' connecting wire on the alternator which; if system had not been shut down; could have led to an inflight fire.day VMC enabled us to make the early choice for shut down of electrical systems. An on board ipad with foreflight provided current VFR charts and confirmed navigation to [alternate].mission was for IFR refresher training; with pilot under hood and instructor/safety pilot. Following electrical system shut down; pilot removed hood to enable both pilots to clear for conflicts.

Original NASA ASRS Text

Title: AA5 pilot reported diverting to an alternate after noting an electrical system anomaly.

Narrative: While under radar vectors for intercept of ILS; ALT warn light came on and system began to show an electrical discharge rather than a charge. To avoid any chance of serious electrical issues and to preserve battery power for landing (radio and flaps); we cancelled IFR with approach; turned to a heading of about 320 degrees; descended to 4500 MSL; turned off all electrical; and proceeded to [an alternate airport] (a location with maintenance facilities for aircraft type). Landed without further incident. Investigation on ground found a 'shorting' connecting wire on the alternator which; if system had not been shut down; could have led to an inflight fire.Day VMC enabled us to make the early choice for shut down of electrical systems. An on board iPad with ForeFlight provided current VFR charts and confirmed navigation to [alternate].Mission was for IFR refresher training; with pilot under hood and Instructor/safety pilot. Following electrical system shut down; pilot removed hood to enable both pilots to clear for conflicts.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.