86 M1009 questions

[dyocis]

I just picked up an 86 M1009 for practically nothing with 36000 miles showing, could be 136 or 236...who knows. The previous owner started to convert to a 12v system and he obviously didn't know what he was doing. My buddy is a diesel mechanic and he is going to fix the wiring and get the engine tuned and cleaned up for me.

My question is should I keep the 24v system or go to a 12v? I've read the write-up on the different options for 12v...ie: 1 alt 2 batteries...2 alts 2 batteries....and 2 alts 3 batteries. I know this is going to be a matter of opinion, so give me some feedback on why you think a particular setup is better than the others.

I'm not planning on doing anything crazy with this rig, 6 inch lift, 37" tires, and a paintjob (someone put a gloss forest green paintjob on it). It won't be put back to original or have big mil antennas on it, but probably will have a big whip CB antenna so when I go out to the desert I can talk to the guys.

Other than that, it will be a weekend toy and my get outta town rig if things go south. I am going to be putting a lot of extra lights on it, but they will all run off 12v.

Tell me what you think, and any other things I should do since its in the shop with a licensed mechanic....Ohh, he owes about 45 grand, so all this is being done for free!

 

[kipman]

Mine is stock 24volt, I have a block heater and a gear reduction starter, I love the way it spins over when it is cold. You do not have to worry about that living in California, but I still say keep the system stock.

 

[Skinny]

If you plan on running lots of electrical accessories, I would convert it back to 24v and make all the lights and possibly winch 24v as well. The CUCV has a killer electrical system when working correctly, stick with it.

 

[CycleJay]

Hello Dyocis,

Keep the 24v stock system.
One advantage I have experienced is, that when one of my alternators stopped working
on a roadtrip, the truck kept running, and got me home safe, because of the other alternator, kept working.

Now when I drove my employers civy blazer on a road trip for work,
his alternator stopped working, and died on the side of the freeway,
and had to be towed back to the office.

And like the guys above have said, it runs great when working properly.
It was built as 24v, so keep it that way.

If you want a 12v electrical system, then buy a civy blazer.
And do not convert the 86 M1009.

Simple as that... Good luck...

Just my $

 

[wayne pick]

Skinny makes an exelent point, Keep it 24v. If you run a gang of 12v off road lights from the front battery you will more than likely run into trouble. The front battery will always be low from the draw of the lights, radios and whatever, and the rear battery will be over charging. Running the lights off 24v will allow the charging system to recover quicker and more evenly. Always run both batteries that have the same CCA rating. Two group 31s is the preferred choice for your aplication. Just my.

 

[georgia mike]

Speaking of offroad lighting, correct me if I'm wrong, but isn't it possible to run two 12 volt lights in series to work with the 24 volt system?

 

[twright]

You need to find a copy of Military Vehicles Magazine Aug. 2010 it tells you how the system works. It is not a 24v system but a 12v, 24v system . If you wire it righr you can run any 12 lights you want including a 12v winch. I can't put the write up on here to long for me to do that .But if you will pm me I will try and tell you how it works.
AEC Wright Retired

 

[Skinny]

You need to find a copy of Military Vehicles Magazine Aug. 2010 it tells you how the system works. It is not a 24v system but a 12v, 24v system . If you wire it righr you can run any 12 lights you want including a 12v winch. I can't put the write up on here to long for me to do that .But if you will pm me I will try and tell you how it works.
AEC Wright Retired

It is a hybrid 12/24v system but running 12v accessories does not utilize the advantage of the 24v system which would be higher voltage and less amperage. That is why the starting system is far superior to the civi 12v system. Anything you install that has a 24v option, take it. I politely disagree with the last post.

 

[Racallahan1]

I just picked up an 86 M1009 for practically nothing with 36000 miles showing, could be 136 or 236...who knows. The previous owner started to convert to a 12v system and he obviously didn't know what he was doing. My buddy is a diesel mechanic and he is going to fix the wiring and get the engine tuned and cleaned up for me.

My question is should I keep the 24v system or go to a 12v? I've read the write-up on the different options for 12v...ie: 1 alt 2 batteries...2 alts 2 batteries....and 2 alts 3 batteries. I know this is going to be a matter of opinion, so give me some feedback on why you think a particular setup is better than the others.

I'm not planning on doing anything crazy with this rig, 6 inch lift, 37" tires, and a paintjob (someone put a gloss forest green paintjob on it). It won't be put back to original or have big mil antennas on it, but probably will have a big whip CB antenna so when I go out to the desert I can talk to the guys.

Other than that, it will be a weekend toy and my get outta town rig if things go south. I am going to be putting a lot of extra lights on it, but they will all run off 12v.

Tell me what you think, and any other things I should do since its in the shop with a licensed mechanic....Ohh, he owes about 45 grand, so all this is being done for free!

Congratulations on the buy. Sounds like one I tried to buy off a dealer who had it on eBay, but he would never accept my offers. Hopefully he realized he wasn't going to get what he wanted for it, and sold it to you for what I was offering or less.

If it is the same vehicle, I remember the guy posted a video that showed a fair amount of rust to be repaired. Hopefully your mechanic is a body guy as well. Good luck and enjoy. I'd love to see what you do with it. Please post lots of pictures.

 

[brokedown]

If he's already started converting it to 12v, I'd just finish the job. You're using 2 12v batteries to get 24v just so you can run a hard to get starter and burn 12v off as heat with resisters on the glow plug circuit. If you don't have some specific requirement for the 24v to be there, it really is as 12v truck under that camo paint. A 12v dual battery system will give you twice the amps instead of twice the volts, with half the alternators.

 

[wayne pick]

twright, Im sure the OP is well aware that the 24v side of the system is for starting and GP functions. I have an electric plow pump on my truck thats I wired to the front battery. It pulls enough amperage to send the volt guage well into the yellow when ever I raise or angle the plow. I switched the pos cable for the pump to the neg side of the rear battery to see if that would help. It had the same result. If there is another way to wire it so the front battery isn't a drawn down so drasticly i'd love to hear it. I plan to switch the pump motor to a 24v unit before winter hits. Im sure it will eliminate that situation. The OP can easily create a seperate 24v circut using a aux fuse box for accessories and not risk killing the front battery.

 

[dyocis]

Congratulations on the buy. Sounds like one I tried to buy off a dealer who had it on eBay, but he would never accept my offers. Hopefully he realized he wasn't going to get what he wanted for it, and sold it to you for what I was offering or less.

If it is the same vehicle, I remember the guy posted a video that showed a fair amount of rust to be repaired. Hopefully your mechanic is a body guy as well. Good luck and enjoy. I'd love to see what you do with it. Please post lots of pictures.

It probably is, I got it through a buddy of mine that knows him. 800 bucks, it worth more than that is scrap!

 

[Keith_J]

It is no different than house wiring, only instead of the middle being ground, the negative of the 12 volt side is ground. You have TWO 12 volt systems, combined you have 24 volts.

You CAN run 12 volt loads off the rear battery, you have to use the 12 volt side for the negative. Meaning BOTH negative and positive must be protected AND switched.

There are many 24 volt accessories out there, from winches to inverters.

 

[dyocis]

Thanks everybody for all the replies. The more I read about the advantages and disadvantages, the more I'm leaning to turning it into a 12v system with each alternator charging a separate battery. It would allow me to have one dedicated power for the starter, and one for everything else.

I'm still up in the air though, if anyone has a good reason why the 24v system is better than running 2 12v systems with a 12v starter and getting rid of the glow plug resisters, let me know. If you break it down, the starter is the only thing that really runs off 24v, besides the 24v bus bars. Like I said, I won't be putting any mil radios in it, and I don't have any other vehicles that run on 24v either so there is no personal advantage to keeping it 24v.

 

[dyocis]

Also, remember the 24v system is already been partially removed...and I'm missing the batteries. If it were running and functioning properly, I would even think of touching it.

 

[wayne pick]

The advantage of the 24v system is it's better for cold climate truck owners like myself. Nothing like a 24v starter when it's 10 degrees and the snow is blowin. In your climate a 12v conversion will be fine if thats what you want to do. A single 100 amp alternator and a group 31 battery should run all your lights and other stuff with no problems.

 

[Keith_J]

Why did vehicles go from 6 volts to 12 in the 1950s? Because you can get more current through the starter, meaning the starter turns over faster.

Back then, battery manufacture was all manual labor, each cell in a lead-sulfuric acid battery generates about 2 volts. So 12 volt batteries were more complex.

Automotive engineers would love to see 48 volt systems, about the practical limit with arcing and the like. 24 is much better than 12.

 

[amphi]

You need to find a copy of Military Vehicles Magazine Aug. 2010 it tells you how the system works. It is not a 24v system but a 12v, 24v system . If you wire it righr you can run any 12 lights you want including a 12v winch. I can't put the write up on here to long for me to do that .But if you will pm me I will try and tell you how it works.
AEC Wright Retired

Here is a link to the article I wrote:
http://www.steelsoldiers.com/cucv/72712-mechanics.html#post902602

 

[Racallahan1]

It probably is, I got it through a buddy of mine that knows him. 800 bucks, it worth more than that is scrap!

Too funny, I offered him $900 at first. He said he could get more than that if he parted it out. I got up to $1400 before I gave up on him. They go around $600-1200 through Government Liquidation in California, so I knew he wasn't going to get the outrageous amount he wanted.

I'm glad it went to someone who will restore it, rather than part it out. Congratulations again and good luck.

 

[erniemigi]

i would keep it as a 24v system and then you can run a lead wire off your front battery to your inside buss bar and have that as a 12v system to run anything you want