No-Load Test
1. Connect the digital multimeter to monitor engine speed.2. Connect the digital multimeter leads across the battery terminals.
3. Read the voltage (base voltage).
4. Start the engine.
5. Run the engine to 1500 rpm with no electrical load.
6. Read the voltage. The voltage should be in the range of 14.1 to 14.7 volts. If the voltage increase is less than 2.5 volts over the base voltage, carry out Load Test. If there is no voltage increase or the voltage increase is greater than 2.5 volt, carry out the Generator On-Vehicle Test. Refer to Diagnosis and Testing. Generator On-Vehicle Tests