M --alternator-- rpm

I have a Delco 12SI conversion on my C, and I occasionally have trouble getting it to energize. I definitely have to rev it to max rpms to get it charging. Even then, it will sometimes not go for me. I'm still not sure what the exact factors are that affect it -- maybe I've just got a finicky one. I tried chasing down a smaller hub, but no luck there. Sometimes restarting the tractor does the trick.

Mine is a 3-wire conversion, so I've got alternator light that makes it really easy to tell when it's not been energized. I agree with the other posters, though -- even without that light, watching your ammeter should be enough. When my alternator is not energized, there's a slight negative value on the ammeter...when it does energize, I get pretty big jump to the positive side that comes down over the next minute or so. (faster if the battery is already charged up)

Good luck,

- David

If it is a standard Delco alternator, as is used in many conversions, it should charge right away, at anything above a slow idle.

If it is a 12 Volt alternator conversion, the voltage at the battery should measure at mimimum, 13.5 volts, and all the way up to 14.75 volts is normal. Below the low end of that range, you have alternator problems.