K 2500 Suburban 4WD V8-454 7.4L VIN N TBI (1995)
Ignition Coil: Testing and Inspection
Ignition Coil Testing
TOOL REQUIRED
J 39200 Digital Multimeter.
Make sure the ignition switch is "OFF."
1. Disconnect the connector and coil wire from the ignition coil.
NOTE: Do not insert the J 39200 probe into the ignition coil connectors. The female terminals could be spread and deformed, resulting in
intermittent operation of the coil. Be sure to make contact with only the front edge of the terminals.
2. Connect J 39200 as shown in image, (1). Measure resistance using the high scale. The reading should be OL (infinite). If not, replace the coil.
3. Connect J 39200 as shown in (2). Measure resistance using the low scale. The reading should be very low or zero. If not, replace the coil.
4. Connect J 39200 as shown in (3). Measure resistance using the high scale. The meter should not read OL (infinite). If it does, replace the coil.
5. Reconnect the distributor lead and wiring to the coil.
