2. Replace the alternator if it fails the test. Follow step "Generator" in the Vehicle Maintenance section of this section. If it passes the test, perform the power output test on the vehicle as follows.
Important: Always check the generator output before assuming that the generator is faulty due to a short to ground on the "L" terminal.
3. Connect a digital multimeter, ammeter and carbon film resistor to the vehicle.
Important: Make sure the battery is fully charged and the carbon film resistor is disconnected.
4. With the ignition switch off, check and record the battery voltage.
5. Remove the wiring harness connector from the generator.
6. Turn the ignition switch to RUN with the engine off. Use a digital multimeter to check the voltage at the "L" terminal of the harness connector.
7. The reading should be approximately equal to the specified 12 V battery voltage. If the voltage is too low, check the "L" terminal circuit for shorts to ground and open circuits that could cause a voltage drop. Correct open wires, terminal connections, etc., if necessary. Follow step "Charging system" in this section.
8. Connect the generator wire harness connector.
9. Run the engine at medium idle speed and measure the voltage between the battery terminals. The reading should be greater than the reading recorded in step 14, but less than 16 V. If the reading is greater than 16 V or less than the previously recorded reading, the alternator must be replaced. Follow step "Generator" Car maintenance in this section.
10. Start the engine at medium idle speed and measure the generator output current.
11. Connect the carbon film resistor and adjust it to obtain maximum current when the battery voltage is above 13V.
12. If the reading is within the 15 amps marked on the alternator, the alternator is OK. If not, replace the alternator. Follow step "Generator" Car maintenance in this section.
13. With the alternator running at maximum output, measure the voltage between the alternator case and the negative battery terminal. The voltage drop should be 0.5 volts or less. If the voltage drop is greater than 0.5 volts, check the connection between the alternator case and the negative battery terminal.
14. Check, clean, tighten and recheck all ground connections.
