98 Blazer Starting issues

I have a 98 Blazer which over the last few months has been not wanting to crank. I turn the key over and the headlights come on, but doesnt even turn over. After popping the hood, I bang on the fuse box and it will start up. So tired of waking up at 4am to have to pop my hood in the dark and bang on things. I replaced the igniton relay hoping that was the problem. Any suggestions would be much appreciated.