As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PROP DEICE CAUTION ILLUMINATED DURING CRUISE. CYCLED PER E/A CHECKLIST, CAME ON AGAIN. RAN GROUND RESET ON GROUND UNSUCCESSFULLY. AIR TURN BACK. LANDING UNEVENTFUL. CDS SHOWED OPEN PHASE C FOR NR 1 TMCU. FOUND NR 2 AND NR 3 BLADES ON NR 1 PROP TO HAVE BAD DEICE WIRE HARNESS. R&R BOTH NR 2 AND NR 3 WIRE HARNESS IAW AMM 61-10-06-000/400-805. FUNCTIONAL AND CALIBRATION IS GOOD. PROP DEICE DID NOT ILLUMINATE. AIRCRAFT RETURNED TO SERVICE.