As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING RUN-UP FOR OIL CHANGE THE ALTERNATOR SWITCH WAS CYCLED AND THE AMMETER SHOWED A FULL CHARGE. IN THE 'ON' POSITION A NORMAL RATE OF CHARGE WAS NOTED. WITH THE MASTER IN THE 'OFF' POSITION THE PANEL LIGHTS BECAME VERY BRIGHT. THE AUTOMOTIVE VOLTAGE REGULATOR WAS REPLACED AND THE SYSTEM FUNCTIONED PROPERLY.