Use on the car or on the bench to accurately test ignition coils. To check an ignition coil, connect the tester to the coil. Set the spark tester (included with the tool) at 30kV gap. Turn on the ignition, then press and release the coil tester switch. A functional coil will produce a spark that bridges the 30kV gap on the spark tester. See www.surespark.com for videos.
