hello there people hope your well. today i fitted my active fli sub and amp built in . the problem i have it works fine with the radio and turns on and with car ignition no problems. but when i select the cd mode there is no power to the sub nothing . the stereo just works as standard. i flick it back over to radio and it works fine again . tried a few different blue wire combinations but cant do it. ive had to hard wire this stereo in . but the main bmw block was cut out by someone so ive not been able to colour match my wires just trying my luck. this is only prob i have so i hope someone can help as ive got this mainly for my cd's not the radio .