Aftermarket stereo problems

I bought a Pioneer CD player to replace the stock cassette player (which had an unlock code and I couldn't figure it out so it was useless).I bought the correct wire harness online along with butt connectors for a DIY job. I stripped the wires about a quarter inch and crimped them in the butt connector matching the colors up and using a lighter to heat shrink. They we're all snug. The one pair of wire where I connect the blue wire with the blue/white wire and also the two ground wires, I used a twist on wire connector since I ran out of butt connectors.(I detailed that incase I've made any mistakes). Then I hooked it all up to the car. The stereo turned on when I pressed a button and the car was on. The Cd player, UBS port, lights and everything on the stereo worked and it was playing music. Only problem was it wasn't playing in the car so I didn't hear any sound at all coming from the speakers. Are my speakers blown or did I do something wrong?