Change the rod (6)
I believe the answer is:
switch
I believe this clue is a double definition.
'change' is the first definition.
(switch is a kind of change)
'the rod' is the second definition.
(I've seen this before)
(Other definitions for switch that I've seen before include "Circuit breaker; change" , "Electrical control - change sides" , "Change course" , "Control for making or breaking connections" , "One may be off" .)