let me get this straight:
There is 12-14 volts on the positive power line going to your amp, and the ground is good, but the amp isn't coming on? Did you check it with a multimeter? What kind of amp is it anyway (brand/model) ? Are you using a line level out from the s2000 head unit, or are you using a converter (speaker level to line level)? What do you mean when you say your s2000 cd player "doesn't work"? Does it spin the disks, or does it not even come on? Really, every detail you can give us about what happens when you try and run your stereo, and how it's connected would be very helpful. BTW... I still want to ride in that GSR.