Raymond failing to start faulty generator (6)
I believe the answer is:
dynamo
'generator' is the definition.
(dynamo is a kind of generator)
'raymond failing to start faulty' is the wordplay.
'failing to start' means to remove the first letter.
'faulty' indicates an anagram.
'raymond' with its initial letter removed is 'aymond'.
'aymond' anagrammed gives 'DYNAMO'.
(Other definitions for dynamo that I've seen before include "Energetic person (colloq.)" , "It generates electricity" , "Electric current generator" , "Converter of mechanical to electrical energy" , "Generator of electricity on Monday" .)