What was found
DURING FLIGHT 3196/3047, LEFT PROP DEICE LIGHT ILLUMINATED. LT PROP HEAT ANN ON IN FLIGHT IN BOTH NORM AND MAX RANGE. AIR RETURN TO MSP. MAINTENANCE TROUBLESHOT AND INSPECTED WIRING FOR BRUSH BLOCK LEADS AND PROP BOOTS, NO DEFECTS FOUND. REPLACED CONTROL UNIT (P/N 660713245) IAW AMM CH 30-61-10-4 S/N OFF 044-98, ON 052-98. OPS CHECK GOOD.