As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT PILOT SMELLED A BURNING PLASTIC SMELL IN CABIN. PILOT TURNED OFF ELEC SYS & SMELL WENT AWAY. UPON TURNING ELEC BACK ON, AMMETER SHOWED DISCHARGE & ALTERNATOR WOULD NOT COME BACK ONLINE. INSPECTED WIRING HARNESS & REPLACED RING TERMINALS ON ALTERNATOR POSITIVE WIRE & SENSOR WIRE FOR VOLTAGE REGULATOR. REPLACED ALTERNATOR. GND RUN UP CHECK REVEALED NO ABNORMALITIES.