If I had to guess, it's one of the 24v B&C Equipment starters as advertised on their website.

Here's the video:
- 2 minutes

Here's a text description: The jackets of some of the large wires are split in several places. It was probably a good wiring to begin-with, by a PO, then someone tried to replace wire and you can see they did a job with wirenuts and what they had (several nuts have fallen off).

I'm supposed to get it running. I've got two new Group 31 batteries, both fully charged.  I've got additional cables, hammer crimper and lugs to replace the half-broken ends or cables that have split jackets in several places. I have smaller-gauge wire to replace what you see.

I don't know if the starter is 24v. It seems a PO wired it as 12v, because there is a jumper wire on the 12v positive to go to both positive lugs in 2 x 12v batteries simultaneously, but that very well may not be original to the electric start conversion. I don't know if the pump is 12v or 24v. I don't know if the alternator is 12 or 24v.

I would like any help in figuring out what the wiring is supposed to be and how to figure out the voltages of the pump and alternator. I've left the old wiring on, for now, as its routing seems to be mostly correct.

Thanks for your time and energy on this one.

That's a Delco 40MT starter. Should be a number stamped on the solenoid that designates 12 or 24v.
Also should be a model number tag on the starter motor itself that can be used to determine if 12 or 24v.

Nothing

If I just try to engage the solenoid, what should the amp draw be if it's a 12v?

Take a voltage reading while cranking with 12v. A 12v starter should crank at 9-10v.
If it cranks below 9-10v you need the higher Voltage.
You will need good cables and connections to run the test.

I can't do that test right now, until I've replaced all the cables. The solenoid test I can do right away, as I only need about 10g wire to do the test.

As soon as I've tested at least the solenoid on 12v, and have a clear DC amp draw #, I'll post it.

Measure the solenoid resistance then I=V/R
 

ohms law if you know the resistance you can calculate the voltage.

just because there is a wire to link the 2 batteries means nothing.
are they connected in series or parallel? series increases voltage. parallel increase current. if its across positive and negative terminals its in series.

it most likely is a 24v unit.

You mention an alternator. Clean it and see if there are any markings. If there are no markings you could probably remove it and take it to an auto electric shop for testing, easier than removing the starter. I think that it is safe to assume that the starter will be the same voltage as the alternator.
Good Luck. Grant.

Old wrote:

Should be a number stamped on the solenoid that designates 12 or 24v.
 
 

Bryan got back to me from B&C. The stamp is directly between the two bolts that hold the solenoid on the starter body.
I can make out:
5561
12V1B 9

So 12 volts!

Wish it was 24... Seems like you could get a lot more energy out of a battery at those voltages to crank it. I will work with what I have.