I have a 2011 Silverado LT extended cab without the bose system. I am installing a JVC KW AV61BT head unit using this wiring harness: http://www.amazon.com/Rp4-gm31-Radi...1-1&keywords=Pac Rp4-gm31 Radiopro4 Interface. Right now my trucks in the shop but I was opening everything up last night and noticed that the speaker wires for each speaker both positive and negative are hooked up to an RCA plug. But the speaker wire that come from the head unit are just two cords. Do I need to add an RCA input to the headunit wires or take off the RCA plug from the harness and go wire to wire? Or is there some other way of wiring this that im missing?