Audio Systems: 98 pontiac rear speakers, rear speakers, bonville

Question
Hi i own a 98 Pontiac bonville ad the from speakers work fine and are great but the rear speakers have no sound and the connective wire to the speaker in the trunk is not lose but i think i could get to the front of the radio but only if i know exactly to and which to switch and i think the wire is ran all the way to the front i just do not know if its connected cause even when i fade it there is absolutely no sound so if you can let me know asap that would be great thank very much
-peter  

Answer
i believe that there was a optinal rear amplifier in some of the vehicles if there was stering wheel controls
maybe the amplifier is defective this box is somewhere in the trunk
and this are the speaker color wires

http://www.installdr.com/Harnesses/GM-Wiring.pdf

sorry i can not help you more