As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) RT DUCT HEATER/PROP DEICE HEATER WAS OPERATING WITH THE "PROP AND DUCT HEAT" SWITCH IN THE OFF POSITION. TROUBLESHOOT AND THEY FOUND A WIRE IN THE TEMP SENSOR HARNESS BETWEEN CONNECTOR P1021 AND THE HEATED LIP HEATER. THE WIRE WAS CUT/CHAFED SHORTING TO GROUND INTERMITTENTLY CAUSING THE OPS OF THE SYS. SHORTED WIRE REPAIRED AND ACFT RETURNED TO SERVICE.