The steps for testing the generator's runaway protection are as follows: 1. Check the connection parts of the generator's external wires for any broken wires, incorrect connections, or short circuits, and use a voltmeter to measure whether there is battery voltage at point B+. 2. Turn the key door to the "open" position, but do not start the engine. At this time, use a voltmeter to measure the voltage at the D+point and observe if the charging indicator light is bright. 3. Start the engine and use a voltmeter to measure the voltage at the B+point of the engine. 4. Turn on some loads, such as headlights. 5. Turn on the main electrical appliances such as air conditioning and car lights. 6. At the third step, if there is no voltage output from the generator, the following methods can be used to check. For generators with excitation D+points, a 2.5mm2 wire can be introduced from the positive pole of the battery. After starting the engine, use the other end to momentarily click on the D+point (within 1 second), and then use a voltmeter to measure whether there is voltage output at the B+point. If there is, check from the third step to the fifth step, At the same time, it is determined that there is an open circuit in the charging indicator light circuit of the entire vehicle (usually due to damaged indicator lights, loose instrument panel rod connectors, and open circuit in the circuit). If there is no voltage output, there is a failure of the generator to generate electricity