Hiya all, ive got a 2006 ford transit connect. There is a very loud humming noise coming from under the fuse box? Even when the van is off. The humming is still there? Ive checked fuses, relays injust dont know what it is. When i looked under the fuse box there was a black circle metal object, and that was vibrating even tho the van is off? Any help would be amazing please thanks