1942 Allis Chalmers Model B

Johnny Ray

I did just that on my '42B and I highly recommend it. I discuss the particulars on my system conversion here. Your hardest part will be the brackets mounting the alternator. If you are not handy in that area, I can link you to a source that sells custom-built mounting brackets to mount a Delco 10SI alternator on a B. I am assuming you already have the standard 6v generator and therefore your engine block has the two tapped bosses for mounting it. Those bosses will be required for mounting the alternator. Otherwise it will become more of an effort, requiring a custom arrangement. My '42B had them even though it was not supplied with electrics from the factory (wartime B), so yours probably has them also. The very early Bs didn't.

If you investigate the cost of an alternator (Delco 10SI), you'll find it to be far less than purchasing a rebuilt 6v generator. Keeping that 3 position switch for the lights can be quite expensive in the future should you need to replace it. Lose it now and be ahead of the game. Same goes for the generator cutout. Keeping that stuff is for restoration purists. You'll have a more dependable system using a modern alternator.

Rod

If you do change, it will cost some money and require making some brackets for an alternator or modifying your existing brackets if you have a source for a 12 volt generator. If you have lights, your bulbs will need to be changed.

It is a lot easier to make the 6 volt system work than it is to switch to 12 volt.