kw transformer

guys, my one KW was being goofy. I thought my track was dirty because my trolley was hesitating and light flickering. but then it was not working. moved the whistle arm and then it ran good. stopped again. but move the arm and ok. NOW, I get nothing. is there something in that whistle...

This afternoon I attempted to run my vintage lionel set. i'm having a problem with the transformer - first, when i turned the knob it started to smoke from the back - appeared to be the wires I was using so I replaced them with a slightly larger gauge wire, now the overload light comes on. I...