What was found
(CAN) FLIGHT CREW REPORTED THAT THE LEFT INTAKE HEATER ADAPTER WAS INTERMITTANT AND LEFT AC "A" PHASE VOLTAGE SHOWED 64-80 VOLTS. AFTER MANY COMPONENTS WERE REPLACED FOR TROUBLESHOOTING, BURNED WIRING WAS FOUND BENEATH THE ENTRANCE FLOOR (WIRING TROUGH) FOR THE AC SYSTEM. THE WIRING WAS REPAIRED IN ACCORDANCE TO SYD 8-24-005. NOTE: AD CF 98-08R2 ADDRESSES SIMILAR PROBLEMS BUT DOES NOTAFFECT THIS AREA OF THE TROUGH!THIS WIRING WAS CHAFED AGAINST THE TROUGH WHICH OVERHEATED AND BURNT THROUGH "A" PHASE. "B" AND "C" PHASE WIRING WAS ALSO DAMAGED BUT NOT A BAD AS "A" PHASE.