Buy a Y splitter and connect it to the same header that the other fan on the radiator is connected to.  Both radiator fans should be running at the same speed anyway. 
please help i just changed all my fans to Corsair i also changed it to Corsair H60 water cooler i currently have R7 , i received this msg and then when i went in my computer the CPU fan seems always working 100% why? [IMAGE]  
Aurora R7, added Corsair H60 water cooler, error