Technical Confirm my understanding, 1946 Cadillac Starter Circuit

I need to confirm that this rebuilt starter is wired correctly. Most of these connections, including the start relay, are within the starter solenoid housing, and I never looked at it before it was rebuilt. See my schematic below of how the whole setup is wired.

My understanding of how this works is:

1. Pressing the start*****on energizes the "start relay", which in turn provides power to both the "energize" and "hold" windings which are wrapped around a common core (not common core math, of course). When the solenoid plunger is pulled, it closes the solenoid contactor and energizes the starter. This contactor, upon closing, also puts a short across the heavy "energize" winding in the solenoid, and the "hold" winding is then subject to the cranking voltage that is present is across the starter windings to ground. The "hold" winding keeps the solenoid engaged until the start*****on is released, or the "starter safety mechanism" comes into play.

What is this "starter safety mechanism"? It's a Cadillac feature. Look at where the start*****on gets its ground. Once the generator begins to create voltage/current (you choose, it does both) the armature post goes from a resistive ground to charging, the cutout relay in the voltage regulator energizes, resulting in battery voltage to both sides of the "start relay" coil, causing it to release. This "safety mechanism" keeps the starter from engaging in case the driver or kid sitting unrestrained in the front seat happens to press the start*****on.

Did I get it right?

 

interesting....could be right, but I don't have the car in front of me any more.

 

Reading this
https://forums.cadillaclasalleclub.org/index.php?topic=150965.0
seems to support the description. Kind of advanced "will not engage when running" concept, wonder why it wasn't adapted more widely. Maybe it kicks off too soon.
Found a 47 diagram, yours makes it more clear what is going on.
http://cadillac.oldcarmanualproject.com/manuals/1947/1942-1947/14-Electrical/image1.html

 

Mopar did the same on some Desoto and Chrysler models in the 40s, maybe50s.

 

I know the solenoid on my 47 is 'strange' and is part of the reason I caution jumping with 12V to people.
I'd guess that I could research the diagram, but no way I'm testing it by pushing the*****on while running!

 

Yes, very similar to the setup Buick used for years. On the Buick, the starter switch was in the carburetor linkage. You stepped on the throttle pedal, the starter engaged and disengaged when the generator started charging. I think they used this setup until about 1960.

 

Cadillac used it through 1950. They used an ignition switch like we’re all familiar with in 1951 where you started by turning the key. I never tried turning the key when it was running though.

 

I'm pretty sure Buick used a vacuum switch to disengage the starter circuit instead of the generator. At least that's how it works on my '37 Special. There are a couple switches in the carb. The starter switch is engaged when you press the accelerator to the floor, via a spring loaded ball that drops into a flat spot on the throttle shaft. There is also a vacuum switch at the carb to keep the circuit from working if the engine is running.

 

Actually Buick used both, a vacuum switch on the carb and generator feed back.

 

In my 1937 Cadillac, the voltage regulator has a 4th winding that will open a set of points when running, these points open the ground connection that the starter relay needs to energise. This way when the engine is running (and generator is charging) the starter will not work.
Well, I guess at this point I should say my car had this feature, many years ago the regulator failed and I replaced it with one that has just three windings so I lost this feature. I just grounded that relay wire at the regulator mounting bolt. This way if I ever find another "correct" regulator I can reconnect it and all will be right with the world.
In "squirrel's diagram, it shows the regulator having just 3 terminals, maybe the armature of the generator provides enough "ground" potential to close the starter relay until it provides output at running speed. On my '37 system, there is a separate coil that opens when the charging voltage gets to a certain level.
My car is a 70 series, I do believe the smaller series cars had a 3 terminal regulator. Maybe these cars used the system in Squirrel's diagram or maybe they did not have any starter interlock at all, I do not know.

 

Guess it's from an era where the engines were quiet and people weren't as educated on don't engage when running or it will cost you. Beats the 'request' nature of switches on modern stuff, but same premise.