Furnace Ideas / Help

Sorry my friend that really does not help. This is because 1, I cannot read some of the wire numbers, which "may" give a clue
2...The board is so integrated that you really cannot read much into it

BUT what I said earlier is still what I'd do---that is, figure out which tap is going live, on heating, and hook the red fan lead to that tap which should be the low speed. Looking at the "taps" rail on the board, not sure what orange is. Normally, red is lowest speed, and black is highest speed.

I don't see connections for a "run" capacitor, but some split phase, low HP motors don't use them.

Some random thoughts
The "tap rail" seems to be the key, and seems to be programmable, but I'd guess you need a proprietary instrument to do so
One of the taps HAS to be coming on live for heating, so the trick is to match that with the red wire
Also, you need at least one other speed connected to the "high speed" or AC tap because 1....if you ever want a summer circulation fan, you can activate the green stat wire and that will bring on that tap--if a fan wire is connected
2....It is also important to have a fan lead hooked to the AC tap, because if the furnace overheats, and trips the high limit, that action normally triggers the high speed tap in an effort to cool down the furnace--if the fan still runs.

If you want to call me, feel free. Send me a PM. Del