As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, NOTICED ELECTRICAL BURNED ODOR COMING FROM HEATER DUCT JUST PRIOR TO BLOWER CIRCUIT BREAKER POPPING, PLACED HEATER MASTER SWITCH INTO OFF POSITION, ACFT RETURNED TO BASE AND TROUBLESHOT SYSTEM. A VISUAL INSPECTION OF SYS AND WIRING DID NOT SHOW ANY DISCREPANT ISSUES OTHER THAN THE BLOWER WHICH NOTED THE FAN NOT SPINNING FREELY. REPLACED BLOWER.