I want to test a newly bought car radio JVC KD-R321 if the car radio is working.The car radio does not come on when I hold the source switch. I have the yellow lead on the positive of the battery, the black lead on the negative of the battery and the one speaker connecte to the front right speaker connections. I also pressed the reset button.The cd player part takes a cd in and but does not play it. What am I doing wrong and what is the accesories wire for?