I've installed probably a dozen AC Commanders, just finished one. The above instructions have always worked flawlessly for me.
I suggest you first test the motor by itself and make sure it's working properly. Wire one brush to the field connection, wire the other brush to one side of the AC power. Wire the ground to the other side of the AC power. If the motor doesn't run, fix that first.
Here's a simple diagram of the motor by itself, ignore the light bulb, it's not needed. 
