How Do I Know If My Ignition Coil Is Bad?
You can determine if your ignition coil is bad by running a test. This will show whether or not current is flowing through the coil. Detailed instructions on how to perform the test are shown here: http://www.youtube.com/watch?v=rJYJ3KvPhhY.
If your ignition coil is bad your car will not start as it will not be able to get a spark. If your car won't start, this can be the first thing to check.
If your car doesn't start, this may be indication that you ignition coil is bad. This is because if your coil is bad, there will be no spark and without spark your engine will not start.