We just got a new used truck (90 F-150 4x4) and we were installing a new head unit and we hooked up the adapters and everything no power checked fuses in truck and head unit both almost brand new. It came with no radio and it has a microphone holder for a CB so we are guessing it had a CB instead of a head unit well we don't know what is wrong with it. Could it be because the CB was put there? If so how do we fix it? If not what could be the possible problems me and my step dad have installed radios/sub's before still no idea. Help please.