CUCV M1009, Gen 2 Light on...

[IYAOYAS]

In my CUCV M1009, 24 Volt system:

*Gen 2 light in dash comes on and stays dimly lit when enginge is running. *Voltmeter stays near the red or in the red, even with high beams and fan blower on high.
* While the engine is in idle, the two new alternators are togeather producing 29.30 volts and near 29.54 volts when engine is in reved up.

According to TM 9-2320-289-20, Table 2-4 Electrical Troubleshooting:
* The Alternators are overcharging the batteries, and states "If Voltage is over 29.1, replace lower alternator voltage regulator..."
* The Mil-Spec Alternators made by AC Delco have built in voltage regulators, just as per the original. The Alternators were producing more voltage, nearly 30 volts, BEFORE I replaced them with two new alternators, and I am still getting to much Voltage to the batteries.

Questions:
* Is their an exteriour voltage regulator in the system after the two alternators? If so where is it and what is the Part Number?
* Does anyone have an idea as to what may be going on, I do not belive it is a bad Voltmeter in the dash, as my multimeter does read a high amount of voltage comming off from the two alternators.

Regards,

IYAOYAS!

 

[donalloy1]

sounds like a bad earth bond. possible bad alternator.

 

[Warthog]

The alternators will put out 14.4~14.7v when they are working properly. Your 29.3 is at the right spot.

The voltage gauge on the dash has a resistor attached to the back of it. They are known to go bad.

 

[IYAOYAS]

Thank you for your reply, I will take another look at the in dash Voltage guage. Per chance would ou happen to know what the NSN, or a comparitable Part Number would be for this Voltage Resistor on the back of the guage?

Regards,

IYAOYAS

 

[IYAOYAS]

*The alternators are new, and installed yesterday, they are both producing plenty of voltage, and the batteries are new red top Optimas with 1000 cranking amps and 800 Cold Cranking Amps, new 24 volt Starter and solenoid were put in a month ago.
* New American made Mil-Spec Glow plugs were replaced less than a year ago.
* If the M1009 sits for more than 11 hours, she is very difficult to crank back up again. The volt meter immediatly bottoms out when attempting to start, and after several very hard cranks, she starts and then the voltmeter shows full charge.
* I have checked the frame to see if I have a lose wire grounding out somewere on the vehicle, and the multimeter shows that I have no stray voltage draining upon the batteries.

...So... The alternators, starter, batteries, belts, and glow plugs are all new. I get plenty of voltage when running. Though she continues to be very stubborn to crank over if the engine is cold (meaning sitting off for awhile even on a warm day).

This is all a fairly new development, and for the past two years she had been starting and running just fine. This is my daily driving vehicle, and am a little puzzled as to what is the cause. I would say that somehow the starter is not getting enough power to crank over, though the batteries read that they have enough to do so, and are being recharged durring the running of the engine. Perhaps their is a communist gremlin inhabiting by wiring system...

I appreciate all of y'all's ideas. When the weather clears up I will check into the Voltage Gauge resistor behind the dash as a possiable malfunction of the gauge, but I still need to fiigure out why she does not want to crank over after sitting for 11 hours.

Regards,

IYAOYAS!

 

[Gottlos]

A little help please... I looked through the manual and couldn't find an answer. The manual says GEN 1 is left and GEN 2 is right. My question is, Am I standing in front of the truck or behind it to determine left and right? My understanding is right door passenger side, left door driver side etc.

 

[Warthog]

A little help please... I looked through the manual and couldn't find an answer. The manual says GEN 1 is left and GEN 2 is right. My question is, Am I standing in front of the truck or behind it to determine left and right? My understanding is right door passenger side, left door driver side etc.

Sides of a vehicle are determined by you sitting behind the steeringwheel.

GEN1 is drivers side - left
GEN2 is passenger side - right

GEN1 charges the front battery
GEN2 charges the rear battery

 

[lindyp38]

i just got my two alternators back from the shop........and yet...my gen 2 light comes on.....as soon as i put lights on....or the heater blower fan on.......kinda weird that the light would come on......even while im driving...it comes on........what am i overlooking?

thanks mario

 

[IYAOYAS]

Would a faulty battery relay (if their is such a thing...) between the battery and the starter cause the volt meter to bottom out when one is trying to crank over a cold engine, and make cranking the engine very painfully difficult? Once the engine has been running for awhile, and then turned off, she cranks right back up. Weather temperature is not the cause, and the glow plugs are new.

Still trying to figure this one out???

 

[lindyp38]

control card....?

 

[IYAOYAS]

To Lindyp38,
I would check to see if you have a dead cell in one of your batteries, and thus are unable to hold the charge that is running off from your alternators. Run over to your auto shop in a box store, and have them to a quick free battery test.

 

[IYAOYAS]

Okay, so the air temperature is just about freezing at about midnight... I hope outside into my M1009, and she cranks up like a dream. BUT I would expect for her to since She last was running before sunset, about 6 to 7 hours ago. When she sits for closer to 11 hours, it is still a painful long attempt to get her to crank over. Like I stated before, she has new glow plugs, new starter, good Optima batteries that hold their charge, two new alternators that are producing plenty of voltage.

* What would cause a 24volt M1009 to start on a cold night with no problems after only sitting for 7 hours, and be a painful, almost impossiable start in the middle of the sunny day after sitting for 11 hours?
Battery Relay? Starter Relay? And now mentioned Glow Plug Control Card?

* I would think that a bad GP Control Card would make it hard to start all the time, am I right on that?

* I think that it has to be a relay that once cools down from having electricity running through it, it does not want to function properly....

Any Thoughts?

Regards,
IYAOYAS!

 

[Utah CUCV]

When you describe cranking hard:

Do you mean the engine turns over slow?

Or do you mean you have to keep cranking and cranking before the engine will start?

 

[IYAOYAS]

After the M1009 sits longer than the majical 11 hours, I have to keep cranking her to start her at all.
When you turn the ignition, the volt meter bottoms out all the way, if you continue to hold the key in the "start" posisition, the starter tries to crank the engine, but the engine will not turn over, and it sounds like I am trying to kill the beast. After three real hard long attempts to crank the engine over, the fourth attempt will often crank over the engine and then the engine will die right out. Finialy the 5th long hard crank, the engine will come to life, and then the voltmeter will go back up to the green zone.

If I cut her off, she will start right back up. I can cut her off and walk away for upto 10 hours, and she will start right back up even in freezing conditions.

So when the engine has not been running for 11 hours or more... I have to keep cranking and cranking and cranking her, and often with breaks inbetween to give my ears a rest. This is a recent event, as she would just turn right over for many years.

 

[Utah CUCV]

You probably have air getting into your fuel line. This will be unralated to the electrical problems. The reason it takes so long to crank is you are cranking the air out of the fuel line. Once you get fuel to the engine, it will fire then quit. Even once it gets going it will take a few seconds to smooth out. This is because the final air bubles in the line cause the engine to run sparadic. Once all the air is out of the line, the truck will start fine until it sits long enough for air to draw back into the fuel line.

Look for and correct fuel leaks. The base plate for the fuel filter is a common culprit. The fuel pump is another.

 

[IYAOYAS]

Utah CUCV,

Great words of wisdom, found a small fuel leak and thus sucking air. Right behind the Passanger side Alternator, where the fuel line (return to tank line) comes off from the engine, right at the point were the fuel line goes from metal tube to rubber hose, the hose clamp needed to be tighten up a bit, as it was soaked with diesel. That might just have been that issue, for that I thank you for your wisdom.

I checked the control cards under the dash (both of them), and they looked to be fine as they are not burned up or smell funny.

I am going to let her sit for 12 hours or so and see if she starts back up with out any trouble.

Regards,
IYAOYAS!

 

[Utah CUCV]

Any update? I have the air in the fuel line problem. I've made some improvements by tightening hose clamps. But I can see my fuel pump and filter base plate both have problems. I haven't got around to replacing them yet.

 

[IYAOYAS]

Tightening a hose clamp on the return fuel line solved the entire issue with hard turn overs like a charm. Thankfully the fuel pump and filter are still houlding togeather. Though as you know once you solve one problem in an old vehicle, you discover another, and now I have notied an oil leak that looks like it is comming from around the oil pan seal.

That does not sit well with me, but the oil is notcomming from the engine block seals or head, but after running for about 6 hours, she is down a quart of oil from a full 7 qts.

Thanks again for your words of wisdom.

IYAOYAS!

 

[lindyp38]

oh..ill do that....i hope not....those are military batteries i bought.........

 

[erniemigi]

If you check the TMs page 269/4-27 it will show you that under the dash just below the ash tray is the location for the voltmeter and gen 2 relays