What was found
ON DESCENT OUT 15 000' FO'S WINDSHIELD STARTED ARCING. TURNED OFF WINDOW HEAT AND THEN WINDOW CRACKED. R & R THE WINDSHIELD TEMP REGULATOR IAW MM 30-42-11-04, R & R THE RT WINDOW HEAT PROTECTION UNIT IAW AMM 30-42-51-04, R & R FIRST OFFICER`S WINDSHIELD IAW MM 56-11-1-04, PERFORMED WINDOW HEAT ADJUSTMENT TEST IAW AMM 30-42-00, ALL CHECKED OK