As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKE-OFF, PILOT SMELLED SMOKE AND LOOKED AT GAGES AND ENGINE OIL TEMP SHOWED "0". PILOT TURNED AROUND AND LANDED. MECHANICS FOUND A LOOSE WIRE ON MAIN BUSS, BROKEN 10 AMP CIRCUIT BREAKER AND BROKEN WIRE AT VOLTAGE REGULATOR. MECHANICS TIGHTENED LOOSE WIRE, REPLACED CIRCUIT BREAKER AND INSTALLED NEW RING TERMINAL AND REPLACED VOLTAGE REGULATOR. OPS CHECKS WERE GOOD AFTER REPAIRS.