Thanks, TRopic6! I found Alan's article, but that appears to be related to TR4A and earlier. But it still explains a lot. My TR250 motor is a bit worn and under powered, so if I can get the new unit to function, I would prefer to use it. If not, I can rebuild it. But knowing that "theTR6 'round' motor' has separate low and high speed brushes, and 'off' actually grounds out the low brush to ensure the blades park correctly" is really helpful. RE: the switch, I've replaced it years ago with a new switch, and from what I can tell, TR6 and TR250 have the same part number. Also, years ago I installed an intermittent switch in the mix. Bottom line: I'm going to have to sit with and electrical meter and TR6 vs TR250 elec diagrams and plot it all out. Ouch. But hey, nothing better to do, right?
DAVE