I'm not a pro at speakers/systems but, I know a thing or two. I hooked up 2 kicker 6x9s, and 2 kicker 5.25s in my 99 ram 2500. The truck has a Kenwood stereo in it and it was there when I bought the truck 2 years ago. I'm not sure of the model number of the Kenwood. All 4 speakers sound great with USB and CDs. But when I try Bluetooth, only the front 2 speakers work, and the back 2 will not. I've tried everything I know to do. Any suggestions?