TrainLarry,

Thanks so much for the link to the detailed pics and the info on the insulating washers!  That turned out to be the problem:  they were missing.  I substituted some of my own and now the flagman is no longer shorting out.  I did get it on eBay, so a previous owner must have "had some parts left over" at some point in its life. 

Now that it's working, I have one other question.  When the train runs over the 1045C contactor, the flagman's arm barely waves, because it's not getting much voltage (it's on a straightaway, so the transformer speed control is set pretty low at that point).  I'd like to give the flagman full accessory power so that the arm raises well up when the train hits the switch, but obviously I can't just mix in the accessory power with the normal locomotive power....I'd think that would mess things up in the transformer pretty badly.

Is there a preferred way with O-27 track and a 1045C contactor to get accessory power to the flagman but leave the normal track power alone?  I read a brief post elsewhere that talked about doing it with an insulated track segment, but then someone else said that wasn't necessary and you could wire it up without that special track.

Thanks for any insight on how to best wire it up!

John

P.S. This site is way cool and full of great info, so I donated tonight, thanks again for this great resource!