Aligns malfunctioning warning light (6)
I believe the answer is:
signal
'warning light' is the definition.
'aligns malfunctioning' is the wordplay.
'malfunctioning' indicates anagramming the letters.
'aligns' with letters rearranged gives 'SIGNAL'.
(Other definitions for signal that I've seen before include "(Railway) light" , "Not noise" , "intimation" , "Nonverbal action or gesture that encodes a message" , "Gesture of communication" .)