I bought a new stereo(pioneer) from Crutchfield a few months ago. What I recently noticed is the sub woofers behind the seats are not working. They do work with the original stereo so there is no issue with them. I recently changed the harness again as per their instructions. The phono jacks front and rear work only on the front. So my guess is there is a common wire that is not receiving a signal but I can not seem to figure it out. I would like some ideas or instructions in what is wrong and a remedy. Crutchfield rep was helpful but they are missing something also.

thanks