What was found
(CAN) DURING TAXI BY MAINTENANCE TO POSITION THE AIRCRAFT ON GATE, THE POSITION SENSOR ELECTRONIC UNIT STARTED TO SMOKE. AT L1 DOOR AFTER LAVATORY, FOUND A TWELVE WIRE BUNDLE SEVERELY CHAFED BY THE LAVATORY DUMP CABLE WHICH RESULTED IN AN ELECTRICAL SHORT BETWEEN A 115 VOLT AC WIRE AND 28 VOLT DC WIRE CAUSING THE PSEU TO SMOKE AND THE MAIN BATTERY CURRENT MONITOR, A.P.U. CURRENT MONITOR, AND THE L1 LAVATORY LEVEL DETECTOR TO FAIL. ALL AFFECTED PARTS REPLACED AND RE-ROUTED AWAY FROM THE LAVATORY DUMP CABLE.