New How To Test A Coil With A Multimeter Pictures. Measuring ignition coil resistance was once a popular test method. The procedure involves using a digital multimeter (set to ohms) to check the resistance of the primary and secondary windings inside the coil.
Then, attach the negative probe to the negative terminal.
Using the ohm function check the primary and secondary sides for opens or very high resistance. If you get a reading the coils is likely to be fine. Connect your multimeter to the positive terminal or pin of your coil, and to the high output terminal that goes to the spark plug. There are a number of ways to test your car's ignition coil without removing it, but the most definitive test is one that removes the coil and tests it with a multimeter.