I replacedthe old factory radio with a new KD-G710 aftermarket JVC stereo head unit. Everything works fine but I am getting a very poor FM reception and no AM reception at all.I don’t know what's the problem. I thought I did everything right,I connected the black ground wire from the head unit to the naked braded ground wire from the car dash. I also have one gray-ish color wire hanging lose from the new stereo, (I think it is the amp. remote wire).
As far as I know the car doesn't come withan antenna....what might be the problem with this poor reception?I would appreciate any help.

 

yeah u have one it's built into the back glass grid. U have a antenna connector like on any radio but this one goes to a module in the back for the antenna grid. Now sence u have an aftermarket radio u more then likely dont have the Dark Green and Red wire which supplys 12 volts to the antenna module.
So give that wire 12 volts and away u go.