[Bigdrumma22]

I had this problem when installing a stereo for a buddy in his tiburon and it was simply me not connecting the power wire for the amp to the wire on the harness. Once connected we had sound! This is typically a blue or blue/white stripe wire. Since your speakers are already connected to the amp (assuming stock), you just need to give the amp the signal to turn on just like the factory stereo did before you removed it. Just curious but did this harness from best buy have a connector on each end, or one connector on one end and loose wires on the other? If the second is what you have... check that blue wire.

Not having sound definitely seems like an amp issue as already stated, so if the wire isn't the problem I guess you have to bypass it. I'm unfamiliar with that model car, but I hope you get it figured out. I've installed plenty of stereos and systems and the smallest simplest things can really piss you off. I'm sure there's a write up somewhere online if these guys can't find it, try doing a search and good luck!