I could make a diagram if I had a machine to reverse engineer.
If you want to be sure of your wiring, get an ohmmeter (or multimeter), and ohm the field coil. I don't know, but I'm assuming the motor assembly has... 5 wires. Did I guess right? 1 common, 2 speeds, 2 wires for the light bulb. Well, here's what you do. Take the armature out of the field. Connect one ohmmeter test lead to one of the brush holders (or wherever the brush gets its power [some brushes have a spring that touch a contact, or a braided wire that's attached to the brush]) then connect the other test lead to each of the wires coming from the field coil. tbh, I'm not entirely sure how much resistance you're looking for, but I'd bet any reading at all would infer a connection. Just be sure to test ALL the wires, to be sure you've got the right wire. Write down your findings and repeat with the other brush holder. I'm thinking - but I'm not 100% sure - that you will find two wires that have no connectivity to either brush holder. That'll be that stupid light bulb winding, ignore those wires.
Now, you want 1 wire from each half of the field coil winding. It may be tricky to visually pick those. From the wires you ohmed, you'll want 1 wire that has connection to only the 1st brush holder and not the 2nd, and a another wire that has only connection to the 2nd brush holder and not the 1st. With the motor assembled, connect those two wires to 120vac and the motor *should* run at some speed.
Alternatively, if you want to skip the above, and/or if you're (rightfully) worried about damaging the motor by hooking up the wires wrong, you could hook it up in series with a light bulb. An actual old fashioned incandescent light bulb. Ideally a 100 watt. It's a little difficult because technically you'd want a bulb of the same wattage as the load you're putting through it, but I don't think you're gonna find a 2000 watt bulb. Anyhow, if the bulb lights up near full strength, you're probably attached to that stupid extra winding in the field coil. I'd say it might not light at all, or very little, if you're attached to the motor properly (or rather on of the two speeds). I hope I'm thinking this through properly. But at least with the light bulb, if nothing else, it will act as a fuse and protect the motor. Though I think it's unlikely to blow the bulb, the bulb lighting fully will indicate a short. Or near short. I suppose it might light the bulb with any connection (because it's not high enough wattage [electricity is hard to think about, so I'm not sure]), which then you wouldn't have learned anything, but you wouldn't have fried the motor, either. Safest bet, anyhow.
I hope I'm helping.
), and wiggle the wires at any at all points, see if there's any response. This is called the 'wiggle test.' You'd be surprised how often the wiggle test yields some kind of clue.
