一 故障现象:一辆扬州大客车在中速行驶中,起动组合继电器突然出现“吱、吱、吱”的急促响声,之后充电指示灯随着响声也忽明忽灭,亮度暗淡。但此时电流表指示充电正常(大约10A左右);将发动机转速提高,响声减弱,充电指示灯也随即熄灭。故障似乎“消失”,但发动机转速降回中速时故障又重新出现。 A fault phenomenon: a Yangzhou bus in the medium-speed driving, the starter combination of sudden emergence of a “squeak, squeak, squeak” rapid sound, then charging indicator with flickering flicker, dim brightness. But this time the ammeter indicates normal charge (about 10A or so); the engine speed increased, the sound weakened, the charge indicator light is also off. The fault seemed to “disappear,” but the fault reappeared when the engine speed dropped back to medium speed.