My Xenon has been humming lately too. I've checked the ground braid....checked the cab over and nothing touching things that shouldn't be from what I can see. Would you guys recommend changing that cap in mine? If so does anyone know where I can order one? Sorry to be a pain...still learning....
Oh...so the odd thing is that the hum is there when you start...but I walked away for 10 minutes and came back and it was gone. Could it be that the transiter is heating up?