What was found
NR 2 ENGINE COWL ANT-ICE SHOWS AMBER TAI INDICATION ABOVE ENGINE INSTRUMENT CLUSTER WITH ANTI-ICE TURNED ON, COWL VALVE OPEN LIGHT ON OVERHEAD PANEL OPERATES NORMALLY AND GIVE PROPER INDICATIONS AS VALVE CYCLES OPEN AND CLOSED. ACFT GROUNDED. PERFORMED TROUBLESHOOTING IAW FIM 30-21, TASK 806, FOUND TAI VALVE FAILED. REPLACED THE NR 2 ENGINE COWL TAI VALVE IAW AMM 30-21-11-400-801, OPS CHECKED GOOD DURING ENGINE RUN, NO AMBER LIGHT, OVERHEAD INDICATIONS NORMAL.