What was found
AFTER FUELING WITH 9600 LBS IN CENTER TANK, TURNED ON CENTER PUMP AND HAD L PUMP LOW PRESS LIGHT FOR CENTER TANK ILLUMINATE. GROUNDED - YES. PULLED/TAGGED 2 EA CBS. INSTALLED JUMPER BETWEEN RH CNTR PUMP A/C WIRING (D804) AND LH CNTR TANK BOOST PUMP REF B737-800 WDM 28-23-11-3 SHEETS 3&4. VERIFIED RH GFI R55 TRIPS IMMEDIATELY WITH PUMP POWER APPLIED. REVERSED JUMPER AND VERIFIED L/H GFI A/C WIRING OPERATES R/H CNTR PUMP NORMALLY. REMOVED AND REPLACED MOTOR IMPELLER REF B737-800 AMM 28-22-41/401. OPS CHECK, LEAK CHECK CHECK GOOD.