Ignition Coil Resistance Check

Turn ignition switch "OFF". Using an ohmmeter set at the low scale, attach leads to ignition coil primary terminals 1 and 15 (wires removed). See Fig 1. Take primary resistance reading.

Fig 1: Ohmmeter Hookup for Ignition Coil Primary and Secondary Resistance Checks, Also Showing Ohmmeter Hookup for Ballast Resistor Check
Courtesy of NOT AVAILABLE
On Mercedes-Benz models, the coil has a pressure relief plug located on top of the coil. Make sure the plug has not popped out. If it has popped out, replace coil.

Set ohmmeter to x1000 scale, then connect ohmmeter leads to negative terminal 1 and coil tower terminal 4 (high tension). Take secondary resistance reading. If either the primary or the secondary reading was not within specifications, replace coil.

Ignition Coil Resistance Specification

Application	Primary	Secondary
BMW	.4
Fiat Strada & X1/9	1.1-1.7	6000-10, 000
Mercedes-Benz	.7	8000-11, 000
Porsch	.33-.46	7000-12, 000
Saab	1.05-1.35	5500-8500
Volvo	1.0-2.0