kw transformer wont shut off after trains are powered down. unit vibrates when plugged in even with no wires being connected.
If it’s a very mild vibration with a low hum don’t worry about it. I’ve got a KW myself and as soon as it’s plugged in it’s “hot,” as you’ve noticed there’s no “on-off” switch.
As long as it’s running the trains with no problems you’re good.
[#welcome]aboard, if no-one’s done so already!
Normal operation.
Lionel transformers never had power switches on them until 1986.
Can confirm. Both of my KWs and all of my 1033s have always been the same way.