Fc stereos being weird
 

So i swapped dashboards earlier this week and since my speakers dont work, i used the same harness just swapped it over to the new dash, also it seems the front speakers work when i bypass the amp but the rears also dont work unless i bypass their amps, is there a wire that turns on the amp that maybe isnt working? I bridged the blue and white wire (which i think is powe) and the black wire and the stereo fuse blew so i know that they are getting power.