Hall Effect Sensor: Testing and Inspection

1. Remove coil wire from distributor and connect to ground with a jumper wire.
2. Disconnect harness plug from ignition distributor.
3. Check voltage between terminals 1 and 3 (outer terminals) of the harness plug.
4. With the ignition ON, at least 9vdc should be available.
5. If voltage is not within specification, repair wiring.
6. If voltage is OK, switch ignition OFF and reconnect harness plug to the distributor.
7. Pull back the rubber boot on the harness plug, and connect multi-meter test leads to terminals 1 and 2.
8. Remove distributor cap, rotor, and dust shield.

Fig. 36 Testing Hall Sending Unit With Shutter Closed:

9. With ignition ON, rotate the engine until trigger wheel window is clear of the Hall generator (generator covered), Fig. 36. At least 4.0 vdc should be available.

Fig. 37 Testing Hall Sending Unit With Shutter Open:

10. Turn the engine until trigger wheel window is aligned with the Hall generator, Fig. 37. 0 - 0.5 vdc should be available.
11. If voltage values are not within specification, replace the Hall generator.
12. If voltage values are OK, check wiring between distributor harness plug and the ignition control unit harness plug.
Dist. pin 1 Control unit pin 10
Dist. pin 2 Control unit pin 24
Dist. pin 3 Control unit pin 4
13. If wiring, and Hall generator are OK, replace the ignition control unit.