is there any way to hook a cd player to the factory amp in my 89 5.0? I took it to the local car audio shop, and he said no, because the amp is "common grounded." therefore you can not hook up the independently grounded pioneer head unit to it. I would like to use the factory amp because i have no budget what so ever, and any amp will help to increase sound quality to a point (correct me if i'm wrong)

I dont know why i couldnt run the speaker off the amp, and then slit the ground going from the amp to the player into 4 sections.

any help is appreciated.

h/u is a pioneer dehp3600
amp is factory ford
pioneer 3 1/2s
pioneer 6 1/2s
infinity reference 6x8s