The first step: check the connection of the external conductors of the generator for disconnection, misconnection, short circuit, and use the voltmeter to measure the battery voltage at the B+ point.

The second step: Turn the key door down to the “on” position, but do not start the engine. At this time, use the voltmeter to measure the voltage at the D+ point and investigate whether the charging indicator is on.

The third step: start the engine, measure the engine B + point voltage with a voltmeter, should reach the following values

Step 4: Turn over part of the load, such as the headlights

Step 5: Turn on the main electrical appliances such as air conditioners and lights

When proceeding to the third step, the generator has no voltage output. You can use the following method to check. For a generator with excitation D+ point, you can draw a 2.5mm2 wire from the battery positive pole. After starting the engine, use the other end to click D+ point momentarily. (Time 1S or less), then use the voltmeter to measure the B+ point with or without voltage output. If there is, from the third step to the fifth step, together to determine the vehicle charging indicator line has a broken circuit (generally the indicator light is damaged) , the instrument panel rod is loose, the line is broken. If there is no voltage output, the generator has no power failure.