my 24v mess

[Wncenergy]

Any help would be greatly appreciated. A couple of mornings ago leaving for work the batteries in my m1009 that I have driven less than 200 miles were dead, so I then made the horrible mistake of hooking up my wife's 12v jeep to my 24v. After wishing the kids farewell I came outside and instantly started cursing at the smoke coming from the hood. I had melted the cable connecting the batteries and the terminals. Being that my wife had to leave for the day I called AAA to purchase their batteries. When the driver arrived and saw my newly fabricated connector and the old batteries he then proceeded on telling me this was a 12 volt system and I had been frying the system all along. Now he seemed very knowledgable and said he had worked on military vehicles in the army. He then instructed me to cut and rewire it parallel. Handing me a handful of cable terminals he left. Shortly after I rewired it and instantly realized after trying to crank it how I made this grave mistake I then tried to undo the madness I created. I then connected the heavy guage red cable and the thin red cable to the positive on the rear battery, ran the negative into positive into the front and the black and ground cable into the negative. Thinking I had solved my problem I cranked it up and drove off. When I threw my service light switch my horn started to blow. I immediately took it to a diesel mechanic up the road, on the way the generator 1 light was on and gen 2 light was glowing and fading. When I reached the mechanic he said he didnt really know much about 24 v and sent me packing. I made it home and let it sit over night. Today I tried to start it with the hood up and noticed the positive on the rear battery smoking melting the terminal. Completely lost, looking at the TM I notice that the thin red cable appears to be running to the negative on the rear battery.
this is how it sits now

 

[Wncenergy]

AAA guy labeled the batteries. I am holding the wire that I had connected to that positive terminal when I drove it and noticed it smoking.

 

[IdahoPlowboy]

I probably am no help on your electrical mess, But If I were you I would find something to hold the batteries in place.

 

[Skinny]

Remove all cabling...start from scratch. Rebuild both alternators and seecwhat happens.

 

[Wncenergy]

Looking at replacement alternators. Found them on amazon. Should I replace the driverside with an isolated ground alternator also?

 

[scottladdy]

Slow down before something really bad happens!

Whoa there my friend! Slow down before something really bad happens.

If you want to do the work yourself, please spend considerable time with the posts on the 24 volt hybrid system in these trucks along with time with your new best friend, the Technical Manuals.

The electrical systems on these trucks are set up such that, in stock configuration, the majority of the truck is 12V and runs off of the drivers side alternator along with the front battery. The passenger side alternator and rear battery are used for starting. The batteries are wired in series to produce 24 volts. Glow plugs and starter are fed 24 volts. Glow plug voltage is stepped down to "normal" voltage by running through a resistor bank mounted to the firewall just behind the air filter.

The front battery negative is grounded to the body/frame like most 12 volt vehicles. 12V positive is taken off the rear batteries negative post and fed through a fusible link that runs across the firewall. The rear battery is isolated. The passenger side alternator MUST have an isolated ground (one that does not ground through the alternator frame), although the military used the same alternator on both sides.

I can't tell from your pics, but check to see if the previous owner performed the glow plug bypass.

If you need this truck in a hurry you will need to pay someone who is able to critically think and has considerable experience with the Chevy CUCV's. Otherwise, slow down and take your time. I can't tell what may have been damaged by all the adhoc re-wiring that has gone on. But most likely your alternators are both bad now. You can buy the parts to rebuild them, or buy them already re-built. Check the posts and the stickies ASAP. Read the one on fusible links.

Keep us posted on your progress. We're all here to help. Just take it one step at a time.

PS, those battery post clamps you are using are intended to be temporary.

 

[alburms311]

The drivers side does not need to be an isolated ground, you van get one for the drivers side only at Autozone, DL7157. I replaced mine recently with this one. The first one I bought went out after a week, the second is going strong so far(lifetime warranty so no hassle with replacement). I did not give them my old one as a core, I am going to have it rebuilt as an interchangeable spare. In your case, I would have them both rebuilt, and if you want, buy the autozone one for your drivers side, then you too will have a spare.

 

[Cucvnut]

I cant read black text.

 

[SouthernSteel]

Any help would be greatly appreciated. A couple of mornings ago leaving for work the batteries in my m1009 that I have driven less than 200 miles were dead, so I then made the horrible mistake of hooking up my wife's 12v jeep to my 24v. After wishing the kids farewell I came outside and instantly started cursing at the smoke coming from the hood. I had melted the cable connecting the batteries and the terminals. Being that my wife had to leave for the day I called AAA to purchase their batteries. When the driver arrived and saw my newly fabricated connector and the old batteries he then proceeded on telling me this was a 12 volt system and I had been frying the system all along. Now he seemed very knowledgable and said he had worked on military vehicles in the army. He then instructed me to cut and rewire it parallel. Handing me a handful of cable terminals he left. Shortly after I rewired it and instantly realized after trying to crank it how I made this grave mistake I then tried to undo the madness I created. I then connected the heavy guage red cable and the thin red cable to the positive on the rear battery, ran the negative into positive into the front and the black and ground cable into the negative. Thinking I had solved my problem I cranked it up and drove off. When I threw my service light switch my horn started to blow. I immediately took it to a diesel mechanic up the road, on the way the generator 1 light was on and gen 2 light was glowing and fading. When I reached the mechanic he said he didnt really know much about 24 v and sent me packing. I made it home and let it sit over night. Today I tried to start it with the hood up and noticed the positive on the rear battery smoking melting the terminal. Completely lost, looking at the TM I notice that the thin red cable appears to be running to the negative on the rear battery.
this is how it sits now
View attachment 409599

As everyone else,Has stated the TM'S are your best Friend.Im not a expert by any definiton,But i can tell you from experience on this forum these Guys and Girls will Give you a hard time seeing that you are a newbie.:] Take it in stride dont let them get to you and READ THE TM'S then and only then if you dont understand something feel free to jump up and ask a question.For the most part you are in great hands the site is awesome and their are many very smart and knowledgeable individuals who will help ya try to figure out some problems and give you feedback.Sit back take a deep breath get yourself a cup of coffee,soda or an adult beverage(be careful as to not get a PWI or a PUI you will be called out on it hahaha and those of you who know what thats is i had to say it:])My point is the system on the cucvs isnt that complicated once you figure it out.From a rookie to the newbie working on a cucv m1008,m1009 i liken it to dealing with a woman time consumeing yes but well worth it.Good luck with your cucv they are defintely fun to drive no matter what variant you own.


24 volts is actually only associated with the starter and slave recepticle in the grille on the pass side of your cucv.As for all other things the m1009 is nothing but a stripped down version of a Civiy k5 blazer in the same year,Your battery closest to the fire wall on the pass side under the hood is only used in starting the vehicle batterys are ran in a series meaning negtive on the first battery is true postive from first battery to negative on second battery and cable from 24 volt buss bar on pass side firewall goes on postive of second battery which gives you 24 volts. DO NOT GET THIS CONFUSED WITH RUNNNING IN PARALLEL thats the way the civiy blazers are set up IT WILL NOT WORK WITH A STOCK CUCV Dont ask me how i know this.The front battery is used for everything else 12volt lights,heater,gauges to name a few items.Both Alternators are isolated ground alternators.However the pass side is the only one that actually needs the isolated ground.You can get a sutiable replacement for the driverside alternator from autozone.I think the mentioned the part number above.GOOD LUCK and if we can help let us know.

Cucvnut your crazy hahah (i cant read black print hahaha you crack me up)

 

[Wncenergy]

Thanks alot guys will keep you updated

 

[meyerhvac]

I converted mine over to a 12 volt system. I used the drivers side alternator and removed the passenger`s. I got a momentary switch for the GP`S relay , and wired the batteries in parallel, replaced the 24 volt starter with a 12 volt.

I payed careful attention to detail in assuring all connections would stay tight and secure for years . I did this for several reasons, 1 being if I were to be away from home and I needed a jump. No one has a 24 volt system,another is that I did not want to spin 2 alternators. Another being that if I were away and the starter or alternator went out I would be stuck,now I have no worries and get better fuel mileage,and have a new starter.

Bite the bullet and just convert it unless you are jumping other 24 volt mv`s with the slave cable,you will be glad you did. I now have put on 35k on mine since, the only glitch I have had is the GP relay went out and I replaced it with a ford starter relay for 25 bucks.

 

[richingalveston]

get us some better pictures if you can, from what I can see there is not a wire from the batteries to your 12 volt terminal block which is located next to the glow plug relay on the drivers side. we also need to see if the 24 to 12 volt resistor is still there and if it is still being used, it is on the fire wall behind the air cleaner. Also get us a picture of your starter so we can tell what model you have. you are not the origional owner and thus it may have been converted to 12volt. take a high def picture of the entire engine compartment if you can so we can blow it up and look at the wiring. take seperate pictures of the wires that go from the passenger side to the drivers side along the firewall.
also get some pics of your alternators and how they are wired.
And get real familiar with the TM's
We will do what we can to help.

 

[SouthernSteel]

WARNING as stated many times by members and posted many times on the forum if you convert your CUCV to 12 volts. (NO ONE ON THE SITE CAN HELP YOU). again Good luck :]

 

[ryan77]

I would find a member near you and provide beer and pizza and repair it! Keep it 24 volt! Im sure theres a ss member near you!!

 

[meyerhvac]

I would find a member near you and provide beer and pizza and repair it! Keep it 24 volt! Im sure theres a ss member near you!!

Why would you want to keep it 24 volt? there is no advantage that I can see unless you are jumping other MV`s with the slave cable

 

[SouthernSteel]

After looking at the pictures.Looks like it was hooked up in parallel.Which would have been ok but he said it was smoking.I wonder if its still original 24 volts if so it should be wired in a series.

 

[SouthernSteel]

Why would you want to keep it 24 volt? there is no advantage that I can see unless you are jumping other MV`s with the slave cable

Its has its advantages to jump others and run inverters to name a few.The second battery which is a constant 14 volts instead of the 12 volts from the first battery is battery for equipment seeing as how the original 12 volts actually drops when a load is put on it.Plus you just got to have patience so far both my m1008s are doing well with 24 volts so im not complaining.

 

[richingalveston]

I thing we need to have the OP get us some more information before we confuse him on if he needs to be 12 or 24 volt. I beleive we need to know what starter he has and the state of his current wiring. Once we get him back on track and his truck running he can the determine if he wants to change anything AFTER he has some knowledge and understanding of his current system.

 

[SouthernSteel]

Well, I dont know about you, but when I drive mine it is usually a road trip. If I break down 500 miles from home with limited tools I can go to the local parts store and get any part for a 6.2 and be running again in short order. I dont have the floating ground 24 volt stuff to worry about. Good luck finding a floating ground alternator at any auto parts store, let alone driving powering 2 alternators on a already horsepower starved 6.2. To each his own I guess, I prefer to keep it simple.

Touche,Diffrent strokes diffrent folks for sure.I have access to a few items im not high dry by no means.I have backups and i use a gear reduction starter talk about a big diffrence.No wheres near the same issues alot of folks have and i have learned to rebuild my alternators so im covered for the most part.:] Though i might add i have thought changeing my 86 army one over as i just want a driver.Been looking for a Civiy suburban or truck with a 6.2 so i can rob everything from it and do away with all the military wiring so im with ya.

 

[richingalveston]

I think this 12volt vs 24volt battle should be moved to another thread, It is not helping the OP at this point.
We are here to help this member not bash each other and confuse his thread.