Ok i bought a car and it already had a stereo with an amp and one 10 inch sub with all speakers on amp so I thought it would be easy to install a deck i already had so i put and the power wires onto the deck, plugged in the RCA wires and all that jazz. I turned on the car and the deck turned on just fine but nothing comes out of the speakers I don't know whats wrong. because there were exactly four wires pluged into the old deck so i plugged those same wires into the new one and i doesn't work please help.

 

ok i figured it out the guy who put it in last labeled the wires wrong. so a good lesson was learned, check your wires.