Ignition Control Module: Testing and Inspection

NOTE: The ignition (Hall) control unit should only be tested if the engine does not start and there is no spark at the spark plugs.
To further assist you during testing, use the wiring diagrams located in CHASSIS ELECTRICAL DIAGRAMS.

CAUTION: Always turn ignition OFF when connecting or disconnecting Hall sender or ignition (Hall) control unit terminals.
Be sure to check the integrity of the wires, connectors, battery terminals and fuses before replacing an expensive component.

1. Be sure ignition coil is in good working order. If needed, test coil first, refer to IGNITION COIL.
2. Turn ignition OFF.

Testing Ignition Control Unit Harness:

3. Disconnect the harness from the ignition (Hall) control unit.
4. Connect a voltmeter between terminals 2 (-) and 4 (+).
5. Turn ignition ON. Reading should be:

Approx. 12 volts

If not, check wiring and connectors for damage. Repair as needed and retest.
6. Turn ignition OFF and reconnect the connector.
7. Disconnect the Hall sender connector at the distributor.

Testing Ignition Coil Voltage (Coil Wiring Shown Disconnected For Clarity):

8. Connect a voltmeter between coil terminals 1 (-) and 15 (+).
9. Turn ignition ON. Reading should be a minimum of:

2 volts

If not, repair wiring or bad connectors as needed and retest.
Voltage should drop to 0 after one to two seconds.
If not, replace ignition (Hall) control unit and retest.

Grounding Center Connector:

10. Using a jumper wire, briefly connect the Hall sender connector center terminal to ground. Voltage must briefly rise to a minimum of:

2 volts

If not, replace ignition (Hall) control unit and retest.
11. Turn ignition OFF.

Testing Wiring:

12. Connect a voltmeter between the outer terminals (1 and 3).
13. Turn ignition ON. Reading should be a minimum of:

5 volts

If not, check and repair faulty wiring or connector to Hall sender. Repair and retest.
14. Turn ignition OFF.
15. If ignition (Hall) control unit passes the testing procedure, it is in good working order.
16. Disconnect all test equipment and reconnect all connectors.