New Pioneer: no power to anything but center speaker.

[shoalsgary]

I installed a Pioneer double din in place of my stock nav receiver in my 2009 A4 B6 Cabtio. I ordered DIN harnesses and adaptors from England. Radio works, gets power properly, but the only sound is coming from the front speakers. How do I get power to the sub ?
(I have a blue/white wire connected to nothing, plus a few extra wires (pink) etc.) I tried connecting sub RCA's to rear RCA's. I tried connecting 12v to blue wire. Nothing from rear.

 

[shoalsgary]

The wires that come out of the chassis wiring harness for the speakers are not the same color as the wires connected to the speakers. This leads me to believe that there is an amp somewhere for the rear speakers. However, the blue wire that triggers an amp from the receiver does not have a corresponding wire on the back of the chassis wiring harness plug. It's beginning to look like my only option is to run new wires from the receiver to the rear speakers. I hate doing that!

 

[shoalsgary]

Apparently there is no sub, even though the speaker wires are different colors at the chassis connector than at the rear speakers. I disconnected the front and rear RCA speaker connectors and there was no change. I still have front speakers but no rear speakers. Apparently. I'm running on radio power only, and need to run direct wires back to my rear speakers