Hello am new here and hope you can help me! have already read some topics but none with my try… I am now really at the end with my Latin… the following problem: In my S60 bj’05 I installed an amplifier + sub which ran also at the beginning wonderful so certainly went 3 months without problems (had the two already in my car before(4er golf), ran over a year without problems) iwann but the sub just didn’t go, new radio bought(suspected on defective a m chinch output) because amp+sub tested both funzen the solution was -> bad mass contact mass placed on other contact then again, however, only for about 3 months…. the remote led lights green even without the one mass cable is connected which probably means that he gets the mass over chinch what is not good now. I close the cable again goes off the lamp. have also tried another amp since the same happens. chinch cables were tested and seem i n order to be. if I look around in the suitcase room I really don’t know where to get some more mass? the cables have a sufficient cross section. fuses are all whole. someone ne idea?? thank you in advance AMP: Mac Audio MPX 4000 1000watt Sub: Magnat Streetracer 3000xxl 1000watt