My AC stop e working and a tech told me it was the blower motor so I went out and purchased a replacement. The replacement said it was a 3 speed and not a 4 like the one I had will that make a difference? The new one didn't have one wire that the other one had and when I asked the person I bought it from they said that is because they were different speeds. Is that true? The Motor did not cut on when replaced but it is not getting hot like the other one was either.

Did you add a new capictor when installing new motor,, is very important,, yes the extra wires are probable for different speeds,, most airhandlers just need 2 speeds,, so the extra wires are just that(extra)