1976 TT, Original Fan motor just replaced, Now all speeds blow the same?

[Mountain-Fly]

I have a 1976 Coachmen Cadet 24ft TT. When I purchased it two years ago everything on it was original with all manuals. The AC fan started to squeel and next stopped working all together. I could not find an exact match for replacement but found one that was very close. I installed the new motor using the same motor speed wires from the motor wiring diagram as that of the old. The new motor did have one extra wire (maybe Neutral) I left it unhooked and the fan and ac all work. The issue is all speeds seem to be blowing the same regardless of what I turn the dial to (High, Med, Low). I am happy I have cold AC again but wondering why the speeds would not be changing?

[Nemisportsman]

Ran into similar issue with wiring in my cabin ceiling fan with light....2 wire existing wiring....modern ceiling fan set up for 3 wire. I suspect you have guessed the culprit. I am sure someone with legitimate electrical knowledge can confirm your suspicion.