Converting 24volt to 12 volt M1009 CUCV

[blazerman]

I am about to embark on the mission of removing all 24 volt power on my 1985 M1009 CUCV. It appears that I can remove the 24 volt alternator, switch the polarity on the batterys, and replace the 24 volt starter with a 12 volt starter, and my conversion should be complete....... I want to install an additional 12 volt alternator for aux. power for lights, etc. Are there any unforseen problems that I should prepare for??? Does anything else need to be done to make the conversion happen???

 

[Westech]

glow plugs will be a problem. You will have to remove the resistor on the fire wall, also the volt gauge will not function any more. And along with all the other electrical problems that will pop up.. Have fun.

Changing over to 12V is not recommended

See: Cucv Wiki - Steel Soldiers::Military Vehicles Supersite

 

[papercu]

A short search would have found http://www.roscommonequipmentcenter.com/news_notes/nn10.pdf
Wayne

 

[blazerman]

Are you refering to the two transformer looking things on the firewall behind the air breather??? Is that what you are calling the resistor???

 

[Recovry4x4]

Are you refering to the two transformer looking things on the firewall behind the air breather??? Is that what you are calling the resistor???

Yup, that is what he was referring to. I'm going to be the devil's advocate here and ask why you want to convert it to straight 12V? You have the unique ability to run both 12V and 24V stuff, a far superior voltage for demanding starts. What is there to gain in this for you? If you don't understand the 24V and are scrapping it for that, pull up a seat and discuss it's merits. It can be converted fairly easy and if you do it right, converted back about the same. As far as reversing the poliarity, I'd not do that. The magic smoke could come out of some components. You would have to move the batts from series to parallel wiring.

Oh, welcome to Steel Soldiers.

 

[blazerman]

Thanks for the info and the welcome!!! And as far as changing the polarity, thats what I was refering to... From series to parallel. The reason for the conversion is that I have no use for 24 volt. I am turning this CUCV into a hunting buggy with an overhead coyote rack with portable spotlights, a 12volt to 110v inverter and any other toy or illumination device I may add.

Also, the resistor's wires have been cut by the previous owner, and does not function. Everything works great on the CUCV, even the blackout lights.

 

[Wrench Wench]

I'd still think you'd be better served by keeping the truck's own native wiring, adding a 24VDC-110VAC inverter, such as this http://travelers-marketplace.com/2300-WATT-POWER-INVERTER-MILITARY-24/M/B000J1ANSE.htm for AC power and a 24V-12V DC-DC converter, such as this 24V to 12V DC-DC Car Power Supply Converter 30A | Virtual Village - US for powering any needed 12VDC devices.

 

[M54a2weasel]

this is the easy way! just drop a second 12v alternator on the truck and run a seprate system. Let the 24v run the truck and the 12v run your lights stero, popcorn maker and winch.

 

[blazerman]

Thanks M54!!! Thats what I had invisioned, however, the truck runs on 12 volt..... The only function 24 Volt is giving me currently is starting power, And 24volt aux. power. I want to change that to 12 volt Aux. power and run dual 12 volt alternators.
Apparently the previous owner installed a 24volt to 12volt relay on the firewall because my resistors are disconnected and I still start on 24 volt power. Can I change the starter and change the batteries from series to parallel, add the 12volt alternator and rock on?? Even my glow plugs run off of the 12 volt side on my CUCV!!

 

[Recovry4x4]

In that case, chop away. The Roscommon link Wayne directed you to has the best way to accomplish the task.

 

[watkinssr]

24v alternator on an m1009? I thought they all had two 12v

 

[blazerman]

The one on the passenger side is 24 volt, and the drivers side is 12 volt. Unless a twelve volt conversion has been done.

 

[Recovry4x4]

The one on the passenger side is 24 volt, and the drivers side is 12 volt. Unless a twelve volt conversion has been done.

This would net you with a 36 volt charging system. The alternators use an isolated ground and the alts are wired in series to provide 24V to the system. Before you filet this sytem up, you should really study it and learn it closer. You may find that you like it. Just as an example. I had a bunch of Ridgid cordless tools in 18 and 24V. Batteries cost more than the tools. I gutted a battery and put a cable on it to attach to the 24V slave plug on the truck. I now have the longest lasting cordless tools in the neighborhood. They run for a day on one charge and if you start the truck, as long as you have fuel. My favorite is the recip saw (Sawzall).

 

[watkinssr]

I am so planning on doing that with my rigid tols and my snapon impact. I've got a dead snapon battery back just waiting to converted.

 

[K9Vic]

The only CUCV that I know of that has a 24volt alternator is the M1010 with two of them and a DUVAC that changed the 24v to 12v. All others have two 12v alternations including the M1009 to make 24v total. The passenger and driver side are both 12v alternators with an isolated ground. Please do more research on these trucks before you butcher it to a 12v system that is not needed. You are checking the passenger alternators 24v feedback side, it is a native 12v alternator, same as the driver side. The only vehicle that really benefits going 12v is the M1010 as it has the DUVAC that is known for problems down stepping to 12v. The 24v/12v system on the other CUCV is safe and you can run 12v accessories on the 12v side of the battery.

I have installed 12v lightbars on multiple CUCV trucks, radios and 12 accessory jacks for GPS and other 12v accessories. There is no need to make it 12v, these are native 12v with a 24v starting system.

 

[m16ty]

Correct me if I'm wrong but I thought the CUCV already had two seperate 12V systems. They combine to charge the 24V batteries but are seperate in every other way. They had a good writeup about they CUCV charging system in the latest issue of MVM.

 

[Recovry4x4]

That is very correct Ty. That article would help our new member to better understand his system.

 

[wiccantoy]

ok we have a truck here at the fire company. they went to a electrinic goro and they changed the truck to 12 volt. it took more time to change the starter than what the guy did on the fire wall. never changed the alts, but we dont have radio's in the truck other than the county portables. we are still running 2 batterys. but i have a blazer for myself and im keeping it 24 volt. better and easier to start when cold and covered in snow. and i believe the inside of the trucks run on 12 volt. havent checked into it yet

 

[wiccantoy]

24V but can be changed to 12V with one change of a wire. All that has to be done is move the wire that goes to the starter (big red one) off the junction block on the fire wall and moved to the + side of the first battery. This should be done only if a 24V replacement can not be found. With the 24V you have the power of both batteries, with the 12V only the first battery.

 

[K9Vic]

ok we have a truck here at the fire company. they went to a electrinic goro and they changed the truck to 12 volt. it took more time to change the starter than what the guy did on the fire wall. never changed the alts, but we dont have radio's in the truck other than the county portables. we are still running 2 batterys. but i have a blazer for myself and im keeping it 24 volt. better and easier to start when cold and covered in snow. and i believe the inside of the trucks run on 12 volt. havent checked into it yet

Everything on the truck is 12volts, the only part that is 24volts is the starter (M1010 has two 24volt alternators and a DUVAC to make 12volts). The inside of the truck is 12 volts. It will not matter if it is -32degree out and you have a 24volt starter. If any of your 12 volt glow plugs are not any good, it will not start. The 24 volt start only makes it crank faster and stronger. It will not make it start any better if the glow plugs are bad.