Alright so i have been trying to install an aftermarket cd player into my girlfriends 1995 Ford Explorer and i have connected the power, ignition, and ground wires and i have also connected the speaker wires. yet no sound....i was thinking that there is a factory amplifier that isnt getting any power so its not sending the audio to the speakers. i tried two different cd players thinking that the first cd player's audio output was fried but im getting the same "no sound" from both cd players. i need help!