I have a hedge trimmer I'm troubleshooting (link) and I'm wanting to rule out the ignition coil. What resistance should I measure across a typical small engine ignition coil? I would have thought down around 50 ohms or less, but I'm measuring up in the Kohms.
migrated from diy.stackexchange.com Sep 19 '11 at 7:40
It typically depends on the model but 50 ohms across the positive wire post and the spark plug wire post would indicate a problem. While I can't definitively answer what range your specific coil should read, it would typically be good to see an automotive coil read ~10,000 ohms for this check.
Where you would see a low resistance is across the primary winding. That would be the positive wire and the negative wire posts. This should read a negligible resistance, think 0-10 ohms (give or take).