As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE RIGHT WING NAV LIGHT POSITIVE AND NEGATIVE WIRES BURNED TOGETHER, SHORTING THE NAV CIRCUIT. THE 5 AMP NAV LIGHT CIRCUIT BREAKER NEVER TRIPPED. AN INVESTIGATION WAS INITIATED WHEN A PILOT REPORTED THAT THE NAV LIGHT SWITCH WOULD NOT STAY IN THE "ON" POSITION.