wont turn on

I just recently installed a new aftermarket radio, and when I finished I noticed none of my interior lights turn on now. They did before. My dash lights and all of my windows can roll up and down (well not the ones that need new window motors.) But anyways. Its been annoying reaching around in...

my right headlight is acting wild! I turn on the switch the left headlight will come on but the right headlight wont come on however! If I go outside and like hit the thing it will come on? Wiring, bad bulb? what do you think?