I have 2003 1500 hd crew cab ls I have replaced the harness in the steering wheel going after, why the 4 moduals were not lighting up I also bought after market and then GM parts of the 4 moduals they still dont light up. we do have power to them there is only 1 wire that does that and the radio and computer works on those controls they just dont light up and nobody knows why. can anyone help. thanks