stock amplifier

I hope someone here can help with my quandry. My vehicle (2010 Kia Soul) came with a premium sound system and the speakers were shot. So I decided to upgrade the head unit (Alpine ilx650) and door speakers. From what I understand the stock amp is pushing 2ohms. I am not certain of the...

Is there any way i can use my stock amp for the rear stock speakers with an aftermarket deck??? or does anyone know a site where i can get wiring diagrams for free? i was thinking about getting a chiltons for the diagrams but i dont even know if it would work... Get back to me if you have any...