Hello guys. I have S3 8l AMK with BOSE. The car was with RNS-D which i sold and bought double din pioneer. The problem is that the radio reception is terrible. In using only FM, but i can't get more than 2 radio stations. I'm using the aerial adapter but there is no difference. Can someone explain me how does the 3 amplifiers and J515 radio selector work. I disassemble the J515 module, open it, but there is nothing wrong with it. How can i test it if it's working or not? Also how can i test the amplifiers? Sorry for my English.