2001 Kia Rio cylinder #3 fuel injector not spraying

i have tested the fuel injector and it is good but it isnt sspraying fuel when turning the engine over. the engine light keeps saying it is the injector.. there is a red and black wire that stays on when the light tester is put on it and a brown wire that doesnt come on at all. should this brown wire light up or not? and where does this brown wire go? to the ecm or to a sensor?????? thanks for this site it has been a huge help!!!!!!!!!!!!!