I have recently added j&m speakers. Front and in saddle bags, also added j&m amp! I'm going to dealer to have my factory radio flashed to get the fader mode working on radio. When I installed amp only had front speakers then put rear speaker in. I ran wires from front speakers to amp back to front speakers. Then out of amp to rear speakers. Now can't fade from front to back because radio not set up to fade f to r. Reason for having radio flashed. Is the wiring harness coming out of radio going to have rear speaker wires to run back to amp thus allowing fader mode to work. Help would be appreciated!