I have a 2000 chevy silverado 1500 z71 5.3L 4x4 and yesterday I went to start the engine and it started cranking and I relized I forgot something inside, so I took the key out but the engine kept cranking with no key in the ignition and the engine wasn't starting. I had to unplug the battery to get the starter to stop cranking over. And now when I turn the key nothing happens at all. Had the battery and starter tested and they both work, I replaced the ignition switch and still nothing, replaced the cylinder key lock and still won't start. Anyone have suggestion as to what it might be wrong?

 

Welcome to the forum. Do you hear any sound at all, not even a little relay click? It sounds like the Starter Motor relay in the underhood fuse block may be shorted out but check the following as well:

10A Crank fuse in fuse block
Park Neutral Position Switch or Clutch Pedal Position Switch, depending on the transmission
40A IGN A fuse in underhood fuse block