My car did not even come with a radio when i bought it several years ago. I decided to put in a nice but simple system. I think i have located the power connection for the old radio. it is a T shaped 2 plug in style. Has 1 red, 2 orange and 1 black. I believe the red and orange are together and the black separate. Hard to see up under the dash to be sure ( i need glasses). Red and orange are hot for the power and illumination lighting, not sure about the black. Is it a ground wire?