How to test your spark plug for resistance:
1. Get a multimeter
2. Set the multimeter on 20k
3. Set the leads (One end on one side and the other lead on the other end). It doesn't matter how they're arranged.
4. You should get a reading on the multimeter.
5. If you don't get a reading then the spark plug wire is bad.

The longer the spark plug wire the higher the resistance.

Look for good conductors