Russel,
I think he has a switch in the regulator wire that will excite the alternator. This is the wire that would operate a "GEN" light on the instrument panel.

Paul,
you don't say what the voltages you have are
1 on the battery terminal on the back of the alternator
a-with the engine stopped,
b-with the engine reved up.
2 on the battery terminals or starter solenoid terminal
a-engine stopped
b-engine reved up

Back in the old days when I put these on tractors too. They told me the Gen light resistance value was important because voltage is going to it (light on). When charging voltage is feeding back from alternator and makes light go out. On my backhoe you would start up, light on, rev it up light goes out ammeter needle shows charge till sensing wire said battery is charged then the light would come back on. (no more charge) Unfortunately I have no experience with 1 wire conversions.
drujinin

The resistance of the idiot light (hey, I like them) is supposed to be able to keep the alternator from backfeeding the ignition circuit and preventing shutdown.

I never noticed a "normal" alternator turning the light back on when the charge rate dropped off from a fully charged battery. I have seen some that glowed weakly, especially noticable at night, so that may have been what was going on, just never thought about it.

OM,
I guess I never asked about the different cut in voltage regulators, and also don't usually have the limitation of a slow speed engine like the CATs have, so have never had much trouble getting one to excite if it was wired up with a regulator plug. Just always hated to rev up a cold engine to start the alternator, so I usually make shift to wire up the regulator. I think our shop installs only "1 wire" regulators, so that may be a low cut in regulator

I'll give it another try this morning after it gets light. .and warms up a tad. Yesterday I did put a VOM on all connections and got the same reading no matter where I put the probe. . about 12.5 volts. Didn't make any difference if the engine was off, running at idle or high idle.

I don't have any load on the battery yet, just the pony motor starter. I'd like to get this straightened out first, then move on to putting direct electric start and lights on the critter. The electric shop I deal with has both a 40MT and a 42MT available in both 12 and 24 volts. According to the tech, he's suggesting the 40MT in 12 volts from a price standpoint. I'm quite sure as time goes on when I proceed with this, I'll be annoying everyone with more questions.

When that new fangled laser tach gets here, I'll check the revs of both engine and alternator drive. At this point, just by ear I'm not sure it's revving up to full speed. Again, according to the tech the alternator is supposed to kick in somewhere around a thousand RPM and start charging and after it starts, it will continue to charge at a fairly low RPM.

Now I'm really bamfoozled. .started it up this morning, waited 'til it warmed up and smacked the throttle wide open. Turned the switch to "on" and thought I saw the ammeter needle quiver. To my surprise, the VOM went to 13.5 volts. I had raised the high idle screw quarter of a turn before starting as well as brazing and redrilling a few holes on various parts of the throttle linkage to get rid of the slop. The engine sounded like it revved a few RPM's higher, so maybe this was the problem all along?

I'm beginning to see where someone has been into this critter extensively. .and I'm not sure whoever it was really knew what they were doing. I guess I'm gonna hafta get a book on this and recheck just about everything. I know that when I got into the steering clutches a while back to free up a stuck clutch, someone had been in there too. .locks buggered up and not put back on right, several bolts holding the lid on twisted off, etc.

I really appreciate all the help and hints. .thank you all,
Paul

I thought you had converted to 24v direct start,thats why I posted the drawings of a 24V system,now I see its your electric start pony that you are working on I posted a sketch I done for someone else below,it is using an oil pressure switch for the exciting circuit cutoff.
AJ

'''''I'm beginning to see where someone has been into this critter extensively. .and I'm not sure whoever it was really knew what they were doing.""""""

Paul, on our grader engine, I could just follow the red silicone gasket maker. Everywhere they had been, there was a heavy coat of it. And like you, I wonder how much they knew about what they were doing.

You'll like having the tach to set the rpm exactly. Unfortunately there's some things about the governor that just have to be replaced if there is too much wear/slack in them.