Nope nothing plays. I have 2 sets of rcas running from the headunit, one for the 4 channel and the other for the mono. Then since I don't have 3 sets of pre outs I have a set of rcas running from the mono rca out. But wouldn't I still get music from the front speakers because I have the rcas running from there? Does it matter if one speaker is still hooked up to the wire harness for the headunit? That's the only one that plays.