Hey man i just installed the Shark Attack II on my GS, but its a 98 so i had a different wire setup, i think mine was like a red, black, and a black with a white line down it. I can't remember which wire i used, but what i did was just use an ohm meter to find out which one was power. If you don't have an ohm meter just im me at chrisrbts91 on AIM and i will get look for you.

But as for the thick black wire that is the antenna. All you have to do is unplug the old thick wire and plug it directly into the new antenna. There is no need for the new antenna cable.

Just to let you know, I believe you got the Shark Attack II with the antenna booster which in my opinion actually got better reception than the stock antenna. I know the original Shark Attack was much worse than stock.