No power to coil

Ignition fuse, ignition switch, loose connection in harness. Check the fuses first, then follow the hot wire back to figure out where it lost juice. I assume you did check that the coil does not have power rather than just noticing that it doesn't have spark, because there's a big difference there between the two. You could give the coil power externally if all else fails, but you would need a way to turn it off to prevent draining the battery and burning up the coil. I wouldn't reccomend that unless it's temporary and just to get you somewhere.