Thanks Bill,

you were spot on.  I didn't notice the little latch and was removing the front of the boiler.  Have found the latch and now the smoke switch.  Just has a gap where the polarity switch might be though.  Guess that doesn't matter.
cheers

Hi,
Have just purchased my first Bachmann engine which  is from is from a White Christmas Set. ((90076)  It is sold as having a smoke generator. The printed manual and DVD seem to imply that it may have a smoke switch behind the smokebox door.  It doesn't have a switch there at all.
Can any body tell me whether this engine has a smoke switch?  or perhaps it doesn't need a switch.  Will the smoke unit burn out if it is run without oil for making smoke?
I am new to G Scale and I don't wish to damage the engine , so I haven't yet tested it.

rcalder