Guide making variant go wrong (9)
I believe the answer is:
navigator
'guide' is the definition.
(I've seen this before)
'variant go wrong' is the wordplay.
'wrong' indicates anagramming the letters.
'variant'+'go'='variantgo'
'variantgo' anagrammed gives 'NAVIGATOR'.
'making' is the link.
(Other definitions for navigator that I've seen before include "Marine explorer" , "Pilot" , "Person steering course" , "course director" , "Prince Henry, say" .)