Not trying to hi-jack the original post but just wanted to elaborate on my scenario since it may be related and i was incorrect in my earlier post.
Again, a Lionel PWC N&W J.
TMCC
Pulmor motor
Fan driven smoke unit
Loop of fastrack powered with a Lionel ZW-C (handle set at full 18v) and 135w brick.
Everything works PERFECTLY in Command Mode (using Legacy remote).
However, in conventional mode, the smoke unit DOES create smoke BUT the fan does NOT come on to force it out of the stack. Instead the smoke just hovers at the opening of the stack like fog from dry ice. The more voltage applied, the more smoke created but still not fan.
Tried sitting in neutral at full 18v. - nothing
Tried attaching a heavy string of cars - nothing
Tried forward, backward - nothing.