As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) WHILE COMPLETING AD CF-1981-25R6, IT WAS WAS NOTED AFTER REMOVING WING PANEL INBOARD OF RT NACELLE, THAT 2 WIRES (P83D0 P83B0) WERE DISCONNECTED FROM THE EXTERNAL POWER TERMINAL STRIP AND BY ARCING, HAD BURNED A HOLE IN THE WING SPAR. A FLEET INSPECTION HAVE BEEN DONE IMMEDIATLY. AN INVESTIGATION IS IN PROGRESS TO FIND THE CAUSE OF THIS INCIDENT.