99 ram new radio problem

I have a 99 ram laramie slt, changing the radio, took a radio from my old car and installed it ... power came on the radio but speakers didnt work. put the factory radio back in and everything worked fine. so i figured the radio from my car was blown. i went and bought a new radio and it is giving me the same problem hooked all the wires up correctly and power comes on, cds play but no sound.. anyone know why?

Make sure you hooked up the remote wire. I dont know if your truck has a factory amp but if it does you will need the remote wire of the new stereo to turn the amps on.