[Lynn Eades]

Bruce, the soft iron pole shoes are the magnets which are energised by current flowing in the field windings. These pole shoes hold residual magnetism. The polarity is easily set up and just as easily reversed.
To polarise the generator, all it requires is to run a wire from the live battery terminal (in the vehicle the geny is to be fitted into) to the field terminal (wire)of the geny. Striking the wire onto the "F" terminal a couple of times will do the job.(expect little sparks)
The process of testing and rebuilding a generator sometimes results in the polarity being reversed. The unit you get back may not have been your one and also may have come from a vehicle that had a different polarity to your veh. This is why it needs to be polarised for your particular vehicle.

BTW, this "residual magnetism" is what voltage "builds" from, when you tow start a vehicle with a dead battery. If you can get the generator turning over fast enough, it will produce enough voltage to fire the ignition. If you keep the revs up the geny will not only produce enough to "fire" the ignition as well as put some charge into the battery.

You cannot do this with a vehicle fitted with an alternator because the design is different and an alternator requires battery voltage to "exite" it. (get the charging started)

Dave, Does you ign. warning light go? If it goes, there must be a complete circuit. I don't have enough knowledge to help you from here.

ASK an auto electrician if you can do this;
What happens if you momentarily touch a wire from the "F" terminal to to the battery? (engine running above idle)
This would be an un regulated generator which will deliver 30 to 50 volts (the geny wont last long at this out put) The field strength regulates the out put.

Does the generator start working? You should be able to detect the engine loading up.
If it then works, I'd say it is the cutout at fault.

Be careful, those are good bits until the smoke gets out of them. Once the smoke gets out, you'll need new bits.
I don't want to cause that.