batteries draining while starting

[keefer]

when i start my m1009 and it doesnt fire up right away, my batteries drain down. i just replaced both of them with exact replacements. 1000/850 cca each battery. also the guy that had it before me took out the two alternators and put a single one in. why would someone do that? im not sure if any kind of starter conversion was done. could the starter be sucking the batteries down?
also, someone with an m1009, when does your truck shift to third gear? mine seems to take a long time to shift. it shifts at about 50 mph. it has 33 inch tires so i know that will affect if but i dont think it should be that much. anyone have any thoughts?

 

[kentuckycucv]

Transmission shift is a vacume line problem... I bet your hoses are rotted,

 

[davidkroberts]

you need to read the TM and troubleshoot. Check the output on the back of the altenator and see if your getting 12v or 24v? Methinks something is fishy in your wiring. I would start chasing down where the hotwire for the starter is going also and check it with a 24v capable testlight also. This is very hard to do without pictures of what is going on.

 

[344lbsofgetdown]

 

[keefer]

you need to read the TM and troubleshoot. Check the output on the back of the altenator and see if your getting 12v or 24v? Methinks something is fishy in your wiring. I would start chasing down where the hotwire for the starter is going also and check it with a 24v capable testlight also. This is very hard to do without pictures of what is going on.

ya i agree i think the wiring is messed up to. im probably gonna take it back to origianal. i would rather have two alternators in case 1 goes bad.

and for the other gentelman, thanks for the advice on the vacum lines, ill check it out, but i thought diesels dont produce vaccum?

 

[keefer]

ok, im getting 12v at the alternator. im not sure how to check the amps on it. i havnt learned how to do that on the multimeter yet. for amps mine goes from 9,1.5, 10 nd 200m. whats the 200m?
im thinking this thing just has some regular old alternator on it.
to answer davids question the red wire if thats what you meant by hot, is going straight to the battery.

 

[davidkroberts]

okay it appears that the red wire from the front battery is going directly to the starter. In that configuaration the starter has been changed to 12v which in itself isnt a problem. The same modification is mentioned in the FAQ thread in the CUCV forum. Im familiar with about half what is done but honestly you are going to need someone who knows more about these trucks than i do. I would PM Doghead if i was you. If he doesnt know offhand from these pics he would probably be able to tell you someone who knows more than i do. Your batteries appear to be in stock configuarion as a 12/24 hybrid system with no way to charge at 24v because of the one 12v altenator. This is just a bit over my head without being able to look at the truck.

 

[Blood_of_Tyrants]

I agree with David, your CUCV has been converted to a 12 v starter and one of the alternators have been removed. I can also see that the resistor for dropping the voltage from 24 to 12 for the glow plugs is missing, again, that just means that the vehicle has been converted to 12v.

What I don't see is the positive and negative terminal blocks on the passenger side firewall. Not necessarily a bad thing if the wire routing is done neatly (which it isn't).

But the easiest thing to diagnose is your basic problem. If the voltage at the alternator is only 12v, then your alternator is bad.

 

[keefer]

I agree with David, your CUCV has been converted to a 12 v starter and one of the alternators have been removed. I can also see that the resistor for dropping the voltage from 24 to 12 for the glow plugs is missing, again, that just means that the vehicle has been converted to 12v.

What I don't see is the positive and negative terminal blocks on the passenger side firewall. Not necessarily a bad thing if the wire routing is done neatly (which it isn't).

But the easiest thing to diagnose is your basic problem. If the voltage at the alternator is only 12v, then your alternator is bad.

so is each alternator a 24volt? or do two 12 volts make the 24 volts? i sure would like to look at one that is put together correctly so i coud copy it! im thinking it might just need another alternator and whatever it is that brings 24v to the starter.

 

[Blood_of_Tyrants]

The alternators are not standard alternators like you find on most vehicles. Those vehicles have the the casing of the alternator electrically grounded to the alternator windings. The GM CUCVs alternators are 12 v each and have the negative terminal electrically isolated from ground.

This allows them to hook up two alternators in series ( +, -, +, - ) so that you get 24 volts when you measure from the "high" alternator to ground and only 12v when you measure from the "low" alternator to ground, with each alternator charging the corresponding high or low battery. The "low" alternator is used for the majority of the vehicle electrical system such as lights, horn, gauges, etc. The "high" alternator was basically used just to keep the high battery for the starter charged.

Why did GM do it this way?To allow them to make the CUCV with as many standard parts as possible and still have the ability to be compatible to jump start or be jump started from any military vehicle.

When your vehicle was converted, the person who did it decided to to keep both batteries and change the battery wiring from series ( +, -, +, - ) to parallel ( + to + and - to -), probably to give extra cranking in the winter, but the second battery is not necessary.

 

[Warthog]

In a stock system, each alternator is 12v and they wired together is series for 24v.

To restore your truck back to stock will require alot or work and money.

You are missing the alternator, brackets, 24v postive treminal block, Negative terminal block, 24v stepdown resister, all the correct wires, etc.

If you decide to restore it, I would buy a parts truck and get the parts off of it.

It looks like your batteries are wired together in parallel. It may be easier to fix the wiring you have and have the alternator rebuilt.

 

[hovenga67]

I have everthing you need to put it back to 24 volt system except for the alternator if you decide to do that. The thing I like the most about the 24 volt setup is how fast the starter cranks. My cucv starts better than my 2002 chevy I had.
Brent

 

[keefer]

on second thought, i think ill just keep it at 12. i like the idea of a 24 volt starter but it did come with a block heater installed so the winter shouldn't be a problem.
The thing i noticed is that the alternator is on the opposite side as it is supposed to be. im wondering if its hooked up right because the drivers side is supposed to be the isolated ground alternator right? there arent any ground straps attaching to it, just the hotwires and a a two wire connector. does anyone know if there is anything in particular that i should look for in a screwed up conversion?
where the pictures i provided good enough to see everything? i can take some more if necessary. thanks for all your help guys!
@warthog, what did you mean by fix the wiring? is there something in particular that is wrong with it, or is it just sloppy?
since i dont have 24 volts anymore, shouldnt i be able to run a standard alternator if i dont have, or cant afford the military one?

 

[hovenga67]

They are both isolated ground from the factory. One is grounded to the block and the other runs to the negative on the back battery. If I remeber right the drivers side runs the front battery normally so it should be grounded the block by a ground strap if it is a factory style alternator.
Brent

 

[keefer]

yes but my question is how is the best way to run it for a 12 volt. should the grounding strap still be on it? right now it is just set up like a normal civilian vehicle. im wondering if the alternator is fine, but just not good for this setup. i would like to know if i can just get an alternator for a chevy blazer.

 

[Warthog]

yes but my question is how is the best way to run it for a 12 volt. should the grounding strap still be on it? right now it is just set up like a normal civilian vehicle. im wondering if the alternator is fine, but just not good for this setup. i would like to know if i can just get an alternator for a chevy blazer.

Does your alternator have the "extra" post on the back of the case? If so it should be a stock alternator and does require a ground wire from the post to the engine block.

If it doesn't have the post then it has been replaced with a civvy unit and is probably "non-isolated". Your picture doesn't show the back very clear.

When I was talking about "fixing" the wiring, I was talking about tracing the wiring you have left, seeing where it is all hooked up and figuring out what the previous owner did. With a stock system I can look at the wiring diagram and tell you which wire to foloow to fix a problem. With your truck all I can do is guess.

Take some closeup pictures of what you have and post them. If you have to use photobucket to make them large enough so we can zoom in, then do it.

 

[keefer]

Warthog, your the best man, that's exactly what I was wanting to know! I haven't found the part number yet, but it doesn't look like the one in the illustration. It is a delco remey though. That tells me its a civilian type alternator. I have no problem with running one of them.

I checked the red control wire that is beside the black exciter wire and its getting 12v. the batteries are reading 12 volts when the engine is running so I suppose that the alternator is the problem.
there is one update though. I found a bad positive battery terminal. its the marine type and it was cracked. I dont believe it was like that the whole time because I took the batteries out several times. however, it now starts better than when I bought it several weeks ago. its like the amperage to the starter is double!
Im gonna start with a fresh trickle charge on both batteries and see what happens. If they drain down, ill know that the alternator is bad. I guess I don't need any more pics because we know this thing has a civilian alternator right? ill send some if you like though.

 

[Warthog]

You should be getting 14.5v when the engine is running.

Since you alternator is a civvy unit, take to the arts house and have them test it. You can replace it or attempt to rebuild it yourself.

More than likely it is the diode-trio which cost a few dollars.

Here is a link to the Delco Rebuild manual. Very easy to follow.

http://www.steelsoldiers.com/cucv/54200-delco-alternator-manual.html


But before you do that....................lets test your wiring.

You said you where getting 12v on the red excitor wire? Is that at all times? What are you getting on the other wire (stock is brown). You should have no voltage with the key off and 12v with the key on. It is PIN#1 on the alternator picture.

 

[keefer]

yes with the key off, i got no volts on the black exciter wire. I got 12 volts on the red wire. both of these were with the key off and i checked them at the connector to the alternator.
with the key on both were getting 12v.
the link that you sent me didn't work but I have the TM that goes over that and the civilian haynes manual. so i should be good right? what kind of parts house can test it? i took the truck to advanced auto and they no longer use a load testing unit. they brought out some little box that is obviously a dummy version of a multimeter. you think napa would have it?

 

[Blood_of_Tyrants]

Call Napa and Autozone and Carquest. One of them will test it.