可能与车内设备有些关系,在我的车上是一点电流声都没有,建议试试这个: http://item.taobao.com/item.htm?id=10767422006&ref=http%3A%2F%2Fsearch8.taobao.com%2Fsearch%3Fq%3D%25C2%25CB%25B2%25A8%25C6%25F7%26pid%3Dmm_28752805_0_0%26unid%3D0%26mode%3D63%26rt%3D1316420083781&ali_trackid=2:mm_28752805_0_0,0:1316420145_4z3_77291042