Ignition Coil: Testing and Inspection

SPARK TEST

Checking For Spark:

CAUTION: To reduce the hazard of fire or explosion, ensure that no fuel leaks exist before conducting this test. Do not check for spark near the battery.

1. Disconnect the fuel pump electrical connector (under rear seat cushion).
2. Start engine and run until it dies.

NOTE: Steps 1 and 2 not necessary if engine will not start.
3. Remove one spark plug and connect to an ignition wire.

Checking For Spark:

4. With insulated pliers, hold threaded portion of spark plug against a good engine ground while cranking engine.
5. Verify that a strong blue spark jumps the gap.
6. If there is no spark, check for battery voltage at the coil positive terminal (terminal "C" of 3-pin distributor connector) with ignition switch "ON."
7. If there is no voltage, check main fuse, ignition switch. Repair the problem as required.

RESISTANCE CHECK - PRIMARY

Testing Coil Primary Resistance:

1. Check primary resistance across coil terminals as indicated on image.

0.58 - 0.86 ohms

RESISTANCE CHECK - SECONDARY

Testing Coil Secondary Resistance:

2. Check secondary resistance as indicated on image.

11.5K - 18.5K ohms

3. Check insulation resistance between primary positive terminal and coil case. It should be 10M ohms or higher.
4. Replace coil if it does not test as specified.