indash removed from truck had to install oem stereo back 2008 gmc sierra?

[mariazepeda]

So i have a 2008 gmc sierra my indash got stolen so i had to install my stock stereo back. My question is i have a sub and amp on the truck but when installed the stock stereo it didnt work what kind of other cable do i need to buy in order for the sub to work with the stock sterero is a 2008 gmc sierra thanks