故障现象一辆2013年产的JNP6900M-1青年客车,搭载潍柴WP7.240E40型发动机,累计行驶里程约为27万km。驾驶人反映,仪表上充电指示灯异常点亮。故障诊断接车后试车验证故障,接通点火开关,发动机顺利起动,仪表上充电指示灯1正常,充电指示灯2常亮,并伴有主发电机异响,使用缓速器时,仪表板上电压表显示电压过低。断开点火开关检查,发动机上安装有2个AVI1417D3002型佩特莱主发电机(图1),采用上下位置安 Symptom A young JNP6900M-1 passenger car produced in 2013, equipped with a Weichai WP7.240E40 engine, has a cumulative mileage of about 270,000 km. The driver reflected that the meter charging indicator light abnormally lit. Fault diagnosis After the test car to verify the fault, turn on the ignition switch, the engine started smoothly, the meter charging indicator 1 normal, charging indicator 2 is always on, accompanied by the main generator noise, the use of retarder, the dashboard The voltage meter shows the voltage is too low. Disconnect the ignition switch check, the engine is equipped with two AVI1417D3002 type Peiter main generator (Figure 1), the upper and lower position security