yea, go get the GM Antenna mate in the same aisle you got the wiring harness and then that should be that. No Antenna plug in, no radio, and it also acts as a low impedance ground.

 

Alright. I haave a radio harness adapter thingamabob...it fits in the aftermarket stereo perfectly.

Still not working fully, I'm missing just one harness for the green and black wires. I havent been able to find it yet.
its the black one that isnt connected to anything.

EDIT: Sorry for the late post btw. P:

 

The black is the ground. If there is no wire to mate it to in the wiring harness then you will have to find a metal surface under the instrument panel to fasten it to. I dont know the green wire is. Speaker wires are green, white, purple and grey.

 

Well the ebay page here looks like what im looking for but for an unbelievably
steep price.

http://cgi.ebay.com/ebaymotors/METRA...Q5fAccessories

i long harness i have but its the square looking one that i probably need.

 

Well 2 things, either you ll have to give up the ONSTAR or bypass the factory amp. What you could do is go to www.scoche.com and see if they have an amplifier interface for aftermarket radio and GM class 2 factory amplifier.

If you bypass the amp you will have to rewire the speakers. If you can integrate it inline with the radio then you shouldnt have to. I wouldnt know it would cost but at least $30 I suspect.

 

Just replaced stereo for my wife's 04 impala too...you can't use the red wire from the harness....you have to pull switched power from somewhere else. I ran a wire to the fuse panel. You should also have a fuse in the line you run. 15 or 20 amp I think...I coulnt understand the black harness either but Ive read that it is for on star so I left it unplugged. Know too, that you wont have the chimes anymore without an extra adapter add on that costs aroun $30. Also you will no longer have access to onboard computer through stereo unless you use a t harness which requires running wires all the way to the trunk where you can plug in the original stereo. Mine works great now.