Military Vehicle Repair: M1009 Cucv starter problem, starter solenoid, voltage starter

Question
I have a 1984 M1009 CUCV.

Was having starter problems, so I replace the old starter with new Delco 24v diesel starter. Worked well for several times. Then I turned the ignition key, heard a hissing sound and it wouldn't turn over.

Now when I turn the key, I hear a single click and nothing else happens.

Any ideas about what has happened? The old starter always worked (just the wrong voltage and had stripped teeth).

Thanks for your help Van.

Answer
Hello Joe,
"The old starter always worked (just the wrong voltage and had stripped teeth). "??

So...what voltage was it?  Had the vehicle been "Converted?"

Let me tell you how the orriginal system works.
The ignition key,(as well as the headlights, wipers,...you name it, just about everything else) is 12 volts. Just like a standard Chevy truck.
But the starter wire from the ignition switch, rather than run directly to the starter solenoid, goes to a relay up under the dash, just about under the ash tray.
That relay is operated by 12 volts, but completes a 24 volt circuit to the starter solenoid, which is 24 volt.

I would suspect that relay under the dash is what you hear clicking, but it could also be the starter solenoid, volt meter relay, or one of the other relays used in some of those military vehicles.

The hissing is very likely a loose connection, which could be the 24 volt wires on that relay, the connection through the firewall, the starter solenoid, one of the battery cables, etc. Could also be that relay internally.

The complete wire system, including the two alternators, isn't all that complex. I have no way of knowing what you still have, though, and the fact that it had a "wrong voltage starter", makes helping from here more difficult, since all I can do is speculate on what might have been rewired for it.

I work on them regularly, so more specific questions are welcome, and I will try to help.

Van