What was found
DOOR WARNING LIGHT ILLUMINATES AFTER TAKEOFF AND WENT OFF AND ON INTERMITTENTLY UNTIL 3500 MSL WHEN IT STAYED OFF. ON APPROACH IT CAME ON AND OFF AT 3500 MSL UNTIL SHUTDOWN. DIVERTED. LANDING UNEVENTFUL. INSPECTED AND FOUND AFT PAX DOOR LOCK SENSOR BLUE WIRE BROKEN AT AREA BETWEEN FUSELAGE INGRESS AND LOCK SENSOR. COMPLIED WITH WIRE REPAIR IAW WM 20-16-00-1 AND 20-16-05. COMPLIED WITH OPS CHECK OF AFT PAX DOOR AND WARNING SYS IAW AMM 52-12-00-710-802. OPS CHECK GOOD. RETURNED TO SERVICE.