head unit problem

[240s13.5]

when i bought my 240 the seller took out his stereo and left nothing there, so i tried to wire my Pioneer Premiere from my old civic into the empty space where the stereo should go, i got everything wired right (even bought the stereo adapter to match up with the nissan wiring harness) and had two rear left and two rear right wires left, so i let them be and capped them off so that they wouldn't touch any other wires, i reconnected the battery and the stereo won't work, the power ant. was working but that is about it, so i checked the fuse in the stereo and it was fine and still wouldn't work, what can i do to fix this problem!?

[ForsakenTH]

the wires that are left...could they be the grounds...you might have wired the grounds into the head unit and the power ones left out as well...im not real up to date on head units but i would check that out.

[240s13.5]

no i installed everything to match up to the old wires and the whole match black to black (ground) and red to red and orange to orange, is pretty easy, but i had 4 wires left...2 LEFT REAR (green)and 2 RIGHT REAR(purple)...for the speakers

[ForsakenTH]

check to see if their is an amp somewhere...i know that when i put my Alpine in i missed that...made it only play radeo and no CD...other then that i cant think of anything