1994 Chevy Lumina coolant fans

I have 1994 chevy lumina euro 3.1 v6 I noticed today the coolant fans werent working it has dual fans and niether one is working I have heard that the fans on some cars dnt start working till the temp guage is 3/4 way but I let it idle till temp guage hit over 1/2 way point and they still didnt come on even turned the a/c on to see if they would do u know at what temp should the fans be coming on?