Ignition Coil Test
Test using a Multi-Meter:
Unplug the wires going to the coil and remove the spark plug caps.
Set the meter to Rx10:
Test the resistance of the primary windings - touch both meter leads to the terminals on the coil. The reading should be low (.5 - 1.5 Ohms) - just checking for any broken wires.
Set the meter to Rx10,000:
Test the secondary windings - touch one test lead to the spark plug wire (spark plug cap off) and the other lead to the (-) terminal on the coil. The readings should be high (6000 - 13000 Ohms).
Be sure to check your service manual for the specs to you your bike.
Test using no Multi-Meter:
Disconnect both spark plug wires from the spark plugs.
Unscrew either one of the spark plugs and stick it back into one of the wire caps.
Lay the plug down on the cylinder head or anything grounded.
With key on, run your starter for two seconds and look at the end of the plug: a nice, fat blue spark = healthy coil. A weak, sick-looking orange spark = dying coil.
1998 DYNA WideGlide
2003 RoadKing Classic
2005 Heritage Softail Classic