As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT APPROXIMATELY 1300 LOCAL AND DURING CLIMB-OUT FROM KGSP GOING TO KSAV THE ALT 2 WARNING LIGHT CAME ON AND SHOW A BATTERY DISCHARGE. ACTION TAKEN WAS TO DIVERT TO KGMU FOR TROUBLESHOOT AND REPAIR. 1 PASSENGER ON BOARD AND LANDED WITHOUT INCIDENT. FOUND THE NR 2 ALT FIELD CONTROL UNIT IN THE MCU 120 TO BE READING HIGH RESISTANCE.