I just picked up a Lionel 224 engine with a 6466W Tender and am having a little trouble with the transformer short circuiting. The engine runs pretty well by itself but when I attache the tender the light on the transformer blinks almost immediately. The rollers on the tender are pretty dirty, would this possibly be the cause of the short? The whistle will go off periodically by itself on the tender as well without any reason. Thanks for any advice, I'm still new to the hobby and learning.