no sound from speakers (no amp) but power to deck
 

Hey Guys, I just installed a new complete stereo into my campervan ( gotta have good tunes whilst travelling / BASE jumping around Canada) anyways, i have never experienced this problem before with any previous stereos but i just installed new wiring to speakers, new speakers both 6x9's and 6 inch splits to a new sony deck... wiring is all good but when deck is playing music i have no sound coming from any speakers.. Any suggestions? my Camper van is a Ford 1977 Ecoline Camper.
Thanks