radio problems

[randle2318]

C prong is not connected to new sony radio of a 1997 C230, could that be why CD palyer, Ipod, and Auxillary not working

I couldnt find this anywhere or maybe I just dont know how to search for things. anyway:
I just installed a sony cdx-gt420ip radio in my mothers 1997 C230. There are 3 different square things that have wires connected to them connected to the stock radio. I used a wiring harness i bought for the C230 for the new radio. Connecting the wires was very srtraight foward matching colors for 2 of square things connected to the new radio but the 3rd square of has no place to connect to on the new radio. I thought it was odd that so many wires didnt need to be used in the new radio but i left it alone.
The radio works fine with FM and AM but the CD and when i connect my I-Pod to the built in ipod docket wire in the back or the auxillary in front no sound comes out. The ipod shows that its connected and the sound meters in the front of the radio move up and down with the music, just no sound comes out.
I was wondering if maybe the square thing with the wires that didnt have anything to connect to is the problem (what are the wires for?) or if maybe its the radio? DO i need to splice those wires together somewhere? Is there a wire schematics anywhere? Please help.

again the radio works fine other than the CD, auxillary jack and the ipod jack