I did the same thing i spend over 2 hours trying to figure out why the bulb didnt work. Make sure the fuse is not burnt out, if the fuse is good then when you install your bulb make sure its making contact right, because if you dont turn them right then there will be no current going to them. When you've done that check that all your wires and plugs in the back of the clock are connected right meaning they snap back into place properly. The final thing to see if your clock light is working is your car has to be on, not just the key turned to where your stereo is working, it has to be completely on and your head lights have to be turned to on also. I didnt figure that out since i installed them during day light hours so i wouldve never got that part. Hopefully this helps