I have not done it with any of our trucks because we find the 24 volt systems to be very reliable. With 24 volts, it takes less amperage to do the same work, so less strain on everything. All parts are available, so no problem there. It is my thought that most conversions are done because someone is uncomfortable with the 24 volt system, mainly because they think there is some kind of mystery about it. They do not want to risk having problems they think they cannot fix with the knowledge they have from working in 12 volt systems. The work and expense of it is just not worth it to us.
Regards Marti
Warsaw, Indiana
4 M-880 Pickups
2 M-200 Trailers
3 M-105 Trailers
2 M35A2 Deuces
1 M-139 5 Ton Bridge Truck
1 M-543A2 5 Ton Wrecker
2 M-51A2 5 Ton Dump Trucks
1 M-52A2 5 Ton Tractor
3 M-135/ M-211 Deuces
1 IHC T-9 SeaBees Dozer
1 M-313 Shop Van
1 M-689 Shelter Dolly Set
The amount of work involved and the pros and cons change depending on which specific model or vehicle family you are asking about. CUCVs are the trucks most likely to be converted to 12V. Which model are you asking about?
Perhaps a thread title change stating the model will get you better responses. Also, there's a lot of info available through the "SEARCH" feature.
If you're worried about winter starting, going from a 24V to a 12V system is flat out the wrong thing to do. You'll need a much bigger 12V battery, and more copper in the wires between battery and starter to crank over the engine when it's cold. Not to mention finding what would be an odd-ball starter wound for 12V operation for this engine. Stick with 24V systems; keep your system charged when not using the truck (two 12V chargers, a 24V charger, or better still run the truck once every couple weeks and keep the system charged). Use a 24-to-12V power converter to run accessories that you want.
-Carl
1971 M35A2 WO/W
1971 M35A2C W/W
Last edited by Carl_in_NH; 11-09-2009 at 15:57.
Reason: Can't type
The Following User Says Thank You to Carl_in_NH For This Useful Post:
Both my Unimogs and my M656 are 24 volts. I use a little 24V/12V converter for things like my laptop computer, GPS, and stereo.
I needed a jump start once on one of my Unimogs. We just put the 12V jump to one battery for a few minutes, then to the other battery. We removed the cables when starting. We were very careful about grounds and connections, and it worked fine.
As far as cold starting, it doesn't get into single digits very often here in Seattle or Blaine. The coldest I've started is about eight degrees. Instead of starting in one second, the engines took about three seconds. The 24v starter really spins the engine.
I converted my deuce to 12 volt. I converted it because everything that I use the truck for needs 12 volt power. I have several civi trailers and an RV/toyhauler that I pull with my truck. Not to mention all of my creature features that I have installed. It only cost me 350.00 to do the complete conversion which is super easy to do. 12 volt starters for these trucks are easy to find. It is a very common heavy equipment starter. It is not an "odd ball ". Fact: the stock 24 volt starters that are in the trucks are actually inferior starters. No matter where I am at now, I can repair my electrical system locally. I live in Ga. But, from time to time it does get below zero here in the winter. The truck starts with no problem. I have never even used the starting aids. The only reason that the military uses 24 volts is for uniformity. They can jump anything from anything.
24volt to 12volt
