Preparing for the test
Turn the ignition key to position «OFF».
Note. In order to pinpoint a fault at the connections, make sure that both outputs or their connections are not disturbed during the test.
Pic. 7.19. Generator output voltage test circuit
Connect a digital voltmeter to the terminal «IN» generator and (+) battery terminal. Connect (+) voltmeter lead to terminal «IN» generator, and (–) voltmeter wire to (+) battery terminal (pic. 7.19).
Conditions for the verification
Start the engine.
Read the voltmeter reading with the engine idling and the alternator loaded (headlights, heater fan, etc.).
Analysis of results
The voltmeter should show voltage drops corresponding to the nominal value.
Rated value: 0.2 V maximum.
If the voltage drop is greater than the rated value (more than 0.2 V), then the cause is most likely a wiring fault.
In this case, check the wiring between the terminal «IN» generator and (+) battery terminal (including fusible link). Check if there is a problem (bad contact) in connectors and connections, changes in the color of wire insulation (due to overheating) etc. Correct the problem and recheck.
After completing the check, let the engine idle. Turn off the headlights, heater fan and other loads, then turn the ignition key to the «OFF».