Hmm! right well that wire is your power wire n should be connected up to your yellow wire on the stereo n then the yellow wire from the dash should be connected to the red wire on your stereo, n also your black (negative) wire should be connected to the thick brown wire in the dash, n how do you mean there is no sound does the stereo light up but theres no sound or is there nothink at all, n have you made sure you'v gone through each speaker singley so you haven't crossed the speakers over i.e made sure that the positive n negative are both from the same speaker on each speaker.

if still no joy n you'v double checked your connection's as stated then the only thing left is to check the speakers themselves, if the unit has power then it should either be the speaker wires or speakers themselves presuming it's a brand new unit,

let me no how you get on