On Monday, December 7, 2015 at 2:33:07 AM UTC-6, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

....do you have *any* search abilities?