Seems a bit wonky to me still - they said Fire at Will was fixed but I'm not sure.
Got interdicted on my Type 9 which is mostly turrets and they didn't do anything after the pirate turned red.
Had to quickly switch to Target Only and they started firing then.
I am pretty sure you have to have them bound to a fire group to trigger them or something like that. I think this was something in the 1.3 change list.