Radio Wiring Help Asap

[john]

A girl at my work has a 90 (I think) s10 pickup. I was going to look at her cig lighter wiring and see if I could get it to work for her. She pulled the radio and center section out. I looked at the wiring without disconnecting any of it. just looked at the lighter wires. Someone tapped the ground (I think, its black) for the lighter off the radio. There is another wire connected to the lighter assm. I told her I could fix it tomorrow for her. She put the radio back in and the cover on and it didn't work. I didn't mess with the wiring at all. Just looked at it. The radio (pioneer cd) will flash on and off but will not play or even eject the cd (what she told me). I am guessing it is a loose ground or possitive wire. Anyone know what color the power wire is generally? I can only thing that it is a loose wire. Anything else it could be? Please help ASAP. Thanks, John