whats the correct way to wire ecu fan control (a12)

[racepak]

hello everyone
whats the correct way to wire ecu fan control (a12) for cars that dont have a ecu fan control (most eu models) ?
i used to just run a wire from pin a12 tapped to the green wire of the fan switch. (red wire) and adjust fan control from software. it worked fine but im not sure of thats the correct way to wire, it, some sources says a relay is required,
thanks

[Spunkster]

As long as there is a relay that is operating the fan then it should work.