Rivarossi 4-6-4 Hudson tender problem

Yes, it has a small wire

Thanks. I took everything apart that I could and then reassembled, checking for these things, and it works now. My daughter is happy that the passenger line of her railroad is back in operation.

I couldn't find anything obvious, so I suspect perhaps it was dust or lint somewhere interfering with the connection.

I was having problems with the tender again, so I took two additional steps. First, I added an additional half ounce of weight to the tender to improve the contact between the wheels and the track. Second, I tightened the pin as much as I could by hand to enhance the connection from the tender to the locomotive. The combination of these two things made a dramatic difference.