M1009 won't start without help

I have a 1985 M1009. I recently had it converted to 12v and Im not sure it was done right. In order to start it now, I have to use starting fluid. I have been told this can cause it to become dependent and thus not want to start on its own. Is this an issue with the glow plugs, glow plug controller, fuel pump, fuel filter, or because it was not converted properly? I do not know what all was done to convert it. Yes that may have been stupid, but I couldn't afford 2 alternators and 2 batteries every time it decided to crap out on me. Any help is welcome and appreciated.

How many batteries and alternators have you had to put in it so far?

Also if you don't know what was done to convert it then I sincerely doubt we are going to be able to help well. It could be that your glow plug resistors were not bypassed and now your glow plugs are only getting 2 volts each or something. Could be a bad glow plug module, or relay, I don't know.

This is Badness in its worst form....

Glow plug diesel + ether = boom. I wouldn't do it.

Excessive ether = ring damage = rebuild = expensive.

I've never viewed a 12v conversion as an improvement. I'd start by returning it to stock and then troubleshooting via the TM or knowledgeable people here. Not knowing what was done to it in the 12v attempt we can't even guess accurately.

williedawg said:

I have a 1985 M1009. I recently had it converted to 12v and Im not sure it was done right. In order to start it now, I have to use starting fluid. I have been told this can cause it to become dependent and thus not want to start on its own. Is this an issue with the glow plugs, glow plug controller, fuel pump, fuel filter, or because it was not converted properly? I do not know what all was done to convert it. Yes that may have been stupid, but I couldn't afford 2 alternators and 2 batteries every time it decided to crap out on me. Any help is welcome and appreciated.

Click to expand...

It sounds like you should bring it back to the one that converted it to 12 V and have him d-convert back to 24. There should be no reason to go through alternators and batteries unless you had starting issues or other issues beforehand. Diesels only need a few things to start. Good fuel delivery, engine compression, heat from the glow plugs when cold and most of all fast cranking speed to build compression/heat to get it to pop. If you have issues with any of these important systems it will tax the rest of the systems. Such as weak batteries with low voltage will tax the starter and make it turn over slower and burn out your starter or starter relay. Also week batteries from cranking to long will tax your alternator trying to recharge those at higher rates. A faulty glow plug will tax your system and send to much voltage to the remaining glow plugs and burn them out also. Everything in the design of your system has to work together.. Change your design and you become your own warranty.

If this is the same 1009 you have owned for nearly 3 and a half years and have not been able to figure out the basics , it might be time to listen to the wife and sell it.

I appreciate all the good advice. Ill try to figure it out. Or as I have been told, get rid of it. Thanks for that tidbit as well. solid advice there. Yall have fun, take care.

Friends don't let friends go to bad mechanics

williedawg said:

I have a 1985 M1009. I recently had it converted to 12v and Im not sure it was done right. In order to start it now, I have to use starting fluid. I have been told this can cause it to become dependent and thus not want to start on its own.

Click to expand...

That right there. See that sentence? Yeah, the one in red. Whoever told you that is a complete idiot, and you should never listen to that person again. If that person is your mechanic, you need a new mechanic.

I have heard a lot of really stupid automotive myths over the years, so stupid that they lave a sensible person just shaking his head.

That has got to be one of the stupidest of them.

Vehicles do not learn behavior. They do not "become dependent".

williedawg said:

Is this an issue with the glow plugs, glow plug controller, fuel pump, fuel filter, or because it was not converted properly?

Click to expand...

This is an issue with idiots who should not be allowed to work on anything more complicated than a box of Legos!! It doesn't work because they screwed up your truck because they have no clue what they are doing!!!

It's just that simple. I have to disagree with dougco on this one. Seriously, you should never go back there. Better to let us help you fix it, because they are likely to do serious damage if they try to put back together a system they do not understand. Find another shop for other matters, and let us help you with this.

Right now it's not starting because they disconnected the GP relay somewhere, is my guess.

williedawg said:

I do not know what all was done to convert it. Yes that may have been stupid, but I couldn't afford 2 alternators and 2 batteries every time it decided to crap out on me. Any help is welcome and appreciated.

Click to expand...

Okay, time for some friendly slapping around here. You let somebody screw up a perfectly good system for no good reason. Where did you get the idea that you are going to be going through alternators and batteries on a regular basis? That's just dumb!

Batteries are easily good for 5 years, unless you do dumb things. Alternators? Longer than that, again, unless you do dumb things. And these are brain-dead easy to rebuild. We have at least one member on this forum who sells the rebuild kits for a great price, or you can buy the parts from ASPWholesale. There are threads here that will tell you how. If you've never done it before, it might take an hour, not counting removal and re-installation. It's just no big deal.

With one battery pushing a 6.2, you are going to work that battery to death and be buying batteries more often than if you had left it alone. Let me ask a question: Do you see all new, and much bigger, battery cables in there? I"m betting not. They just re-used the existing cables, right? Yeah, those are sized for the amperage requirements of a 24v system. A 12v system needs to push more amperage to do the same work. Twice the amperage, in fact. Which means you need to upgrade your cables or you are going to be starving your 12v starter for power, which means it will wear out prematurely, and by the way, won't give you reliable starting.

Yes, a 12v system CAN be just fine, but there's a right way and a wrong way to do it. I'm betting these clowns did it the cheap and dirty way, which is going to cause you grief.


I don't think you need to get rid of it, but you DO need to stop listening to bad information. And that shop is a source of very bad information.

If you want to go back to the shop and get any leftover cables & parts back from them, I'm willing to talk you through fixing it back like it should be. I'm sure others will be, too. If you can follow instructions, you can learn.

By the way, I just noticed that you have been a member for almost 6 years, and have only posted 10 times. Either you really know what you are doing, or, for whatever reason, you don't ask the right people for help.

If you are going to take the word of "mechanics" who obviously have NO clue, rather than asking a forum filled with people who know these vehicles inside and out, well, expect to continue to have problems.

Get on here and ask, and we'll gladly help you. If you don't want to do that, well, rsh4364's advice is looking pretty good.

Take some pics of the wiring, especially the GP relay, and we can see where we stand. If you don't know how to post pictures, learn. It's not optional.

So many messed up CUCV's. So little time. So many correct parts going to waste.

Hello all. This brings a question to mind I have had and have spent more than a few hours looking for. Are there any threads on converting from 12 back to 24 volts? I have found this mentioned only a few times. If there are any threads about this I have missed them and apologize for missing them. I have an 1986 M1009 that has been converted to 12 volt. No wiring appears to be missing or cut. I replaced the glow plug controller, glow plug relay, instrument cluster printed circuit, had gen 2 rebuilt, and tested the glow plugs. The truck starts as it should. I have accumulated the passenger side alternator brackets, and just this past weekend picked up a core isolated ground, correct part number alternator at the Findlay military show for $20, I thought that was a good deal. I am looking for a core 24 volt direct drive starter. Thank you for your time.

I don't know of any threads on it, but the TM does lay out the wiring quite well. If the vehicle was converted using the Roscommon method, you can check the documentation on how it was done, to figure out how to reverse it.

You could start your own thread (HINT! HINT!) and be the first.

I have put 4 batteries in it, and had the alternators rebuilt once and replaced once.

It has been hard on alternators, starters, and batteries. I even had to have 1 of the starter bolts helicoiled so it could be bolted on because the hole was wallowed out and stripped. It actually seemed to hold, even though the mechanic said he'd never heard of such a thing.

I was going through batteries and or alternators like crazy, not an idea, I was.

It may sound silly but if I were having issues like that and at wits end, I would take it 500 miles north and leave it with Cucvrus for a few weeks. Guaranteed you'd get back a superbly running CUCV that would be 100% correct.
I apologize that I can't offer help or advise, there's just too many variables as to what's been changed on the starting circuit/electrical system.
I know its frustrating but don't give up, keep pushing forward and find the problem. Tenacity is a good tool to have when chasing electrical problems,,,,,,,, as well as a meter

Well, clearly you had problem that needed to be fixed, but 24 volts was not part of that problem. Now that your shop has been in there, we may never know. OR, we might stumble across it as we try to get this mess sorted out.

I see two possibilities:

1. They did a horrendous job and it's so messed up it really needs to be put back to original condition.
2. They did a reasonable job but they messed up something with the GP system and if we can get it sorted out you'll be okay.

I'm sure there are a bunch of us willing to help you figure out which situation you have, but we can't do anything unless you work with us. The first thing we need is a bunch of pictures of what you have. If you don't have a smart phone, buy an inexpensive camera and figure out how to get the photos onto your computer. (It's easy.)

Get some pics of the battery wiring, the alternator wiring, and the glow plug wiring.

Post them here and we'll wade into the mess and see what we can figure out.

You also need to check basic GP relay function. Check this post for info.

williedawg said:

I have to use starting fluid. I have been told this can cause it to become dependent and thus not want to start on its own.

Click to expand...

My M1008 and I finally had "the talk" about his ether habit. After getting past the normal crap about being in Desert Storm and how bad Saudi diesel tastes and how irresponsible the average PFC drives, he finally admitted to me he knew he had a problem and was ready to make a positive change....