I put an Alpine CD player in my wifes 99 Tahoe. I used the pigtail kit so there would be no cutting. Anyway everything seems to work right except when you put in a CD the rear (door) speakers don't work. The cargo area speakers work, but not the two doors? All 6 speakers work correctly when listening to the radio? I am completely confused. i have done several installs before and this is a first for sure. Anybody seen or heard of this?