What was found
(CAN) CAPTAIN HAD A WINDSHIELD HEAT FAILURE. DIVERSION INITIATED BACK TO DEPARTURE STATION. TROUBLESHOT IAW TSM 30-42-00-810-801-A. FOUND CONNECTOR 3DG1-A NOT FULLY CONNECTED TO LT WINDSHIELD. RESISTANCE OF BOTH LT WINDSHIELD TEMP SENSORS CHECK OK. RESISTANCE OF HEATER ELEMENT OK. WIRING FROM WHC NR 1 TO LT WINDSHIELD CHECKED OK. PLACED ACFT IN "AIRMODE" IAW AMM 32-00-00-860-001-A FOR 15 MINUTES WITH POWER SUPPLIED TO WINDOWS. ALL COCKPIT WINDOWS WARMED UP OK. NO FAULTS. WHC 1 AND 2 BITE TEST OK THROUGH CFDS. RETURNED ACFT TO NORMAL. WINDSHIELD HEAT CHECK`S OK.