Will do, thanks again Bob!!!
I think “reverse the connections to the 8251-50” is too simplistic. I’m not familiar with this controller and assumed that it was a two-terminal device. I see that it has four wires; so I don’t know what would be the proper way would be to reverse the whistle-signal polarity. If anyone has any information about this device, like an owner’s manual or repair manual, would you mind posting it?
Bob do you think it’s possible to use a DC transformer separate from the main transformer or does it have to be an AC transformer to operate the horn? I currently only have to trains that have horns, 8352, 8355 (horn is in this one) and a 8632 steam engine.
You can roll your own horn/bell button, I wouldn’t recommend trying to do this with a separate transformer! How would you wire that?
The horn button (8251-50) has the four wires, figured it could just be hooked up to another power source and work independently of the way Bob had me rewire the track to supply constant voltage to the 1121 switch. Probably not though? I’m overly concerned I will ruin something or send momma flying into the second floor from an explosion in the basement without confirmation from people who know what there doing. [:D]
NO, the horn button should NOT have a separate power supply! All the power to the track has to go through the horn button whether it’s running or not.
Here’s a home-made horn/whistle controller: http://www.jcstudiosinc.com/BlogShowThread?id=412&categoryId=559
Here’s another one: 
Thanks for the info! I believe I know someone who can make some sense of this. [:)]
That looks familiar. Here’s my original post in this forum: http://cs.trains.com/TRCCS/forums/p/185196/2030793.aspx#2030793
The schematic diagram shows only one of the momentary switches. There should be one in each diode string if you want both whistle and bell control.