What was found
SEA - AFTER TAKEOFF AT SEVERAL HUNDRED FEET, NR 1 FUEL TANK FORWARD PUMP LIGHT ILLUMINATED IN CONJUNCTION WITH A 'POP' FOLLOWED BY SMOKE IN THE COCKPIT AND AN ELECTRICAL SMELL. RETURNED TO FIELD AND LANDED UNEVENTFULLY. FOUND SHORT CIRCUIT BETWEEN OPEN AND CLOSED WIRE OF NR 1 ENGINE SHUTOFF VALVE AND THE 115 VOLT AC RETRACT WIRE FOR THE OUTBOARD LANDING LIGHT. REMOVED AND REPLACED FUEL SYSTEM MODULE ASSEMBLY. OPERATIONAL CHECKED NORMAL IAW MM. (M)