Military Vehicle Repair: M1009 Starter questions, starter solenoid, volt system

Question
My 1009 CUCV's old starter had damaged teeth on the starter gear and would make a loud grinding sound every 3 starts.

When I removed it the label said that it was 12 volt starter.

First question: Would a 12 volt starter work with the original 24 volt system?

I replaced the starter with a Delco 24 volt gear reduction starter and it worked great... for one day then it promptly blew the starter relay and neutral switch. That was replaced, then the starter burned out. I put the old starter back in and it worked fine (except for the grinding). I have now installed a cutoff toggle switch between the relay switch and the rest of the system to bypass the relay when the vehicle is running.

Question 2: In you opinion should I just get a regular 12 volt starter (cheap) or another Delco starter ($220). Do you reccomend a good 24v starter and a place where I can get it?

Thanks for you  help

Answer
Hi Joe,
Sounds like someone did some converting, and if that is true, it will be very hard to help from here.
Some volt meter work is needed for sure.
First, what is the voltage at the big cable to the starter solenoid?
Second, what is the voltage at the small wire to the solenoid when the ignition switch is turned to start?
If both are 24 volt, then a 24 volt starter is what you need.
As far as the neutral switch, just the fact of 12 or 24 volts...it wouldn't care.

The relay above the hump, behind the edge of the dash, is a 12 volt relay as far as the pull-in winding. The other two contacts are isolated from the operating, or pull-in circuit, and would operate 12 or 24, or most any other voltage, as long as there isn't a short on the wire to the solenoid.

Generally speaking, everything on the vehicle is stock 12 volt Chevy pickup circuits, except for the starter circuit.
The alternators are even BOTH 12 volt...The diff is the left one grounds to the block, and charges the front battery, and the right one grounds(?) to 12volts, and charges the rear battery.  Believe me, they are interchangable, but watch the ground.
UNLESS someone has done some modifications, like I mentioned above. Few people understand that system, and want to remove all the 24volt, and convert to 12 volt. That can be done, but it is necessary to modify the starter system.
A 12 volt starter could operate on the 24 volts, and would spin the engine like crazy, but the 12 volt solenoid couldn't take it for long, if at all.

www.Memphisequipment.com has all the military parts. But again, the voltmeter tests are what you need first.
I am running 6 surplus trucks, and keeping them stock military. 3 ea 1008's, and 3 ea 1010's. Had a couple 1009's, just don't have them now, but they were great, and exactly like the 1008.

Van