TC reported counterbound train 1 headlight not working. TC of Train 415 checked and confirmed B sideheadlight not working. ~~~~~ 3645: Counterbound TC reported headlight not working. TC of Train 415 confirmed B side headlight not working. CE : 3645 BS Headlight not working.  3645 B/S headlight replaced. Security/function check - OK.  Hanafi 44433