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https://photos.smugmug.com/Cars-and...9d7d06/M/Charging%20System%20Types-M.jpg[/img]
There are two types of charging system used on these old cars and trucks (see diagram above, copied from an old Sun manual).
Type A uses a generator whose field is externally grounded. The generator in the
Type B system is internally grounded. The reason I care is that test hookups for generator and regulator function are different, depending on the type of system in place.
As I understand it, to test which type you have, first measure resistance between Armature and Field terminals, and then between Field and Ground terminals. On the
Type A system, the first measurement (A->F) will be lower than the second (F->Ground). The opposite will be true on the
Type B system.
On my 1953 3100 truck, I have Generator #
1100018, which is the 45 Amp 6-volt unit. When I measured resistances per the above, I got 1.8 Ohms (A->F) and 1.4 Ohms (F->Ground). This tells me I have the
Type B (internally grounded) system in the truck.
So to the electrical gurus on the site, I ask: am I correct?
[btw: I don't seem to be able to directly post a photo, only a link to my SmugMug page. Not sure what I am doing wrong.]
