Step 1: Inspect the external wiring connections of the generator for broken wires, incorrect connections, or short circuits; use a voltmeter to check for battery voltage at the B+ terminal.
Step 2: Turn the ignition key to the "ON" position without starting the engine; use a voltmeter to check for voltage at the D+ terminal and observe whether the charging indicator light is illuminated.
Step 3: Start the engine and measure the voltage at the generator's B+ terminal; the reading should meet the specified values.
Step 4: Switch on partial loads, such as the vehicle's lights.
Step 5: Switch on major electrical components, such as the air conditioner and lights.
If no voltage output is detected at the generator during Step 3, the following troubleshooting method may be used: for generators with an excitation D+ terminal, connect a 2.5 mm² wire to the positive terminal of the battery. After starting the engine, momentarily touch the other end of the wire to the D+ terminal (for less than 1 second), then use a voltmeter to check for voltage output at the B+ terminal. If voltage is present, proceed with the checks from Step 3 through Step 5 and identify the open circuit in the vehicle's charging indicator light circuit (common causes include a burnt-out indicator bulb, a loose instrument cluster connector, or a broken wire). If there is still no voltage output, the generator is faulty and failing to generate power.
