What was found
UPON TURNING ENGINE ANTI ICE ON FOR ENGINE #1 NO BLUE LIGHTS SEQUENCED. TAI INDICATION WAS PRESENT ABOVE # 1 ENG N1 DISPLAY. FOUND P18-3 A7 ENGINE 1; ENGINE & WING CONTROL CB HAD POPPED - RESET CB FOR ICING CONDITIONS WE ENCOUNTERED. GROUNDED - YES. PERFORMED WIRE RING OUT PER B737-900 WDM 30-21-11. REMOVED AND REPLACED MW0313 HARNESS REF B737-900 AMM 71-51-03/401. PERFORMED ENGINE COWL TAI VALVE TEST REF AMM 30-21-11-400-801, AND OIL QUANTITY TRANSMITTER TEST REF AMM 79-31-014-400-801-F00. REMOVED AND REPLACED ENGINE 1 COWL TAI VALVE REF AMM 30-21-11/401. OPS CHECK AND LEAK CHECK OK. GROUND VERIFICATION SUCCESSFUL. VERIFIED CIRCUIT BREAKERS REMAIN CLOSED (P18-3, A6 & A7) AND SYSTEM OPERATES NORMAL.