Upgrading from alpine system 4th gen

[Lilivan22]

First time doing this, i have the factory alpine system 2011 ram and i just bought a 4 channel/1 channel/aftermarket stereo, i have everything Hooked up but no sound is coming out, am i missing something, do i need an interface? i dont know much of car audio

 

[mtnrider]

Did you bypass the factory amp? How did you hook it up?. I suggest you take it to an expert since you don't know much about it.