For some reason the ignition wire coming off of my wire harness doesn't get any power. As of right now my after market CD player has only constant power, it does not turn ON/OFF with the car. I want to run a new ignition wire. Do I run one from the fuse box? If so how do I do that? Is there another way? I'm trying to be especially careful not to fry anything out in my Cadillac. Thanks for any help.