I can't tell from your pictures, but the generator looks somewhat like an early Delco alternator, but it could also be a Leece-Neville alternator. Alternators were used on emergency vehicles that had high electrical loads, with Leece-Neville being a common supplier. The AC boxes in one of your pictures indicate use with a 6-volt alternator, which also indicates use of an alternator on the truck. If the truck has an alternator, look for one of two indicators: either a dry-plate rectifer assembly, a foot or so long, in front of the radiator, or six diodes in the rear frame of the generator. The diodes may look like thin hex bolts, 3/4" or so in size (I don't remember, specifically), that don't seem to hold anything in the end frame.
The dry-plate rectifier typically is an assembly of square plates, 3 or 4 inches square, that have either discs or smaller plates alternately located between the larger ones. The dry-plate rectifer will also have large wires attached to it from the generator- there may be three wires from the generator. If you can find the part number on the generator, I'm sure you can find information on it, but I wouldn't start changing anything until you find out what you have. You could end up with an unnecessary nightmare.
Harvester
