John, or Tom - Is there a way to get the extra fluid out of the fan? Can I get the fan that could be gummed running again? Or, do I have to replace the fan?
Note: Before I embarked on writing all that follows, I should have said that maybe there's a simpler solution in getting some "Eliminator" fluid from JT's Megasteam to put in your smoke unit. It has been known to eliminate clogging from excess smoke fluid although this won't work if for some other reason - like a power wire that has worked loose - your fan motor is not spinning.
If this is the problem, it can be fixed by the user but means getting at the smoke unit inside the loco's body shell. It then has to be detached from the mounting holding it to the shell, the fan (impeller) removed, then the fan motor and both of them cleaned up if they've become saturated with excess smoke fluid.
Along the way I suppose you might find that one of the power wires to the fan motor has got detached or the funnel attaching the smoke unit to the outputs has been misaligned, but checking to see if you have any fan motor sound will probably tell you if that's the problem.
If you've done this before on other O gauge engines it's not a hard job. If you haven't done it, start by identifying the Lionel SKU for your engine (e.g. 6-84110, which is one of their Lionchief Plus GP7 versions) and go to the replacement parts page of Lionelsupport.com to see an exploded parts view. Here's what the smoke unit for the model whose number I have given looks like:
Part 5 is the set of screws holding on the smoke unit PCB. They have to come off to expose part 9 (fan/impeller) and under that will be part 4, the tiny screws that hold the fan motor in place. Taking off the PCB should reveal whether there is fluid residue in the fan housing, which might have seeped down into the fan motor.
Alternatively send it to one of the repair techs on this forum!