I just saw your video. You have smoke, as others have said the fan isn't working.
To add to laid off sicks statement. A fan that runs off of jumpers still may not operate off of the voltage from the smoke unit board.
I have a legacy Berkshire that was offered at the same time this gs 4 was.
The fan on my Berkshire quit 6 months after I bought it. A couple drops of oil on the fan motors bushing behind the impeller worked in by spinning it with my finger got it to work again.
Having said that, given the age of the Loco at this point, I'd probably just replace the fan motor. It's only a few bucks.
Fan motor failures are very common with Lionel.
While your at it, order some new wicking and replace it as well. Over time, the wicking will burn no matter how much fluid you ad and will need to be replaced, nature of the beast.
