My new head unit won't work

Question

I have a 1997 pontiac sunfire. I bought a Kenwood MP538U head unit and i installed it today. All the wiring seems to be correct the fuses are not blown and the battery is connected. I hooked up the head unit and it won't even light up. We put in the old radio and now that one doesn't even light up. I thought it could be the theftlock thing on the radio but it would at least illuminate and say something would it not?