Think I'm going to lose it

[akonitony]

Did ya check the air in the tires?

My way of looking at it is the definition of voltage, or potential, in a circuit is what's the most important thing in making sure that circuit will be completed when it is needed. This is why I would think the military asked for a 24V sytem for the starting ability of these trucks in the field. The 24V potential to the GPs and starter solenoid is a hard system to improve on for reliability. If you have decent batteries and a couple of good altrnators, the odds of that system failing and being able to be fixed with a simple jump are probably astronomical. Why someone would want to change that stultifies the thinking man.

 

[ODdave]

You're right, voltage is pressure, amperage is volume. Horsepower, or watts, are derived values that are independent of any single aspect of a particular system. You absolutely can draw too much current and cause the voltage to drop. In this case, our system is how much work can a starter do in a given amount of time. We are adjusting the voltage and the current details but the amount of work that is able to be done is the same when the bendix gear hits the flywheel regardless of which one you have.

If I have a circuit that can handle 100 amps (high quality 4 gauge wire's max rating on its best day) without creating any significant resistance and I run it at 24v, I can effectively dump 2400 watts of goodness to some device if it will draw that without any issue. I can briefly over run this circuit with an additional 45 amps if the device draws but for every second I run the extra 45amps, I'm increasing the temperature of the wire which is increasing the resistance of the wire feeding the device...which requires even more current in order to maintain the 24v line pressure I'm running. In practice, it would take a good while to do this with just a 50% overrun on the wire specs. No voltage drop is likely within the 2-3 seconds needed to start a properly maintained 6.2.

The same circuit running at 12 volts, would require an additional 190 amps over the rated wire's 100 amp limit to deliver the identical 3.5kw the device will draw. The temperature of the wire will rise much faster and subsequently draw even more current much quicker than the 24v system. It would very easily begin to cause a voltage drop because the wiring simply cannot support the volume the starter needs in order to output 3.5kw to the flywheel. This voltage drop from the rated 12v the starter is designed for, translates to a slower cranking speed.

I have invested $15 in some 2 gauge wire and some wire lugs. I can run more than double what the stock system would handle on its best day with the nicest wiring in the world and I do not experience the voltage drop that causes the output to the flywheel to drop below 3.5kw. As a result, my engine turns over just as fast as anybody else's and fires up within 2-3 seconds no problem. I can also get a boost from some one in a parking lot if I need it.



as an aside;

My 7kw example made previously was a simple response to the statement that one is simply halving the time the power is available instead of halving the current necessary to effect the same amount of power. It was not meant to add any confusion, just to illustrate what I saw incorrect in the original statement I was replying to is all.

thats great but explain how a 0-90 volt dc motor operates in ie. a cnc machine? variable speed=varied voltage, or explain the light bulb test that i mentiond? or better yet, even more closely related, why is it when i jump the ole' 9N ford to mow the lawn and use my 24v m35 to jump off of the starter turns much faster???????????

 

[Swede]

ok, im not trying to be an ass........ but the I.B.E.W. logo is cracking me up....

Thats fine. My field is commercial industrial. I do not usually deal with sissy wire anything under 12awg. i usually deal with 500mcm switchgears and so on. I deal with Power in and to buidings. I have a problem with going against my knowledge of standard colors that would keep me alive. Black in my field isnt a ground/grounding line.. Black in my field will get you killed depending on the run your dealing with. color codes that I have in my head keep me alive, I cant go against my instinct when looking around in a vehicle( no need to reprogram myself )

With that being said. The truck was 24v when I bought it ran great for about a year. Then it wouldnt start. Starter was fine took it to a shop he tested it and cleaned it. Then checked everything else even bought new plugs,gp relay starter relay, replace it all. nothing. SO then I bought a new GP controller and harness, nothing. So I said WTH and went for the conversion.


did the conversion nothing. Im tired of working on it because everything I do gets me more pissed off due to the fact it should work. Now it sat, and More **** is wrong with it...............

I will try some more but i think if i cant fix it next 2 weeks 2 options diesel mechanic , or swap out diesel for gas............. hate to do it, but have plenty of people that can work on them.

 

[Swede]

I also pulled the starter yesterday and bench tested it .. it is good...

 

[dstang97]

Look up doghead starter relay. Even though you did the 12v conversion I think it will be useful.

 

[stampy]

Uh, you said it wouldn't start......Dumb question but does it turn over? Could be the glow plugs as once one goes they can all cascade due to over voltage. BTW expect a little ribbing when you post with an electrical question and you are an electrician...we all know that no one knows everything...

 

[stampy]

If it does turn over then give it a "small" shot of either to see if it starts. If it does then it's almost definitely glowplugs.

 

[dmc-4359]

thats great but explain how a 0-90 volt dc motor operates in ie. a cnc machine? variable speed=varied voltage, or explain the light bulb test that i mentiond? or better yet, even more closely related, why is it when i jump the ole' 9N ford to mow the lawn and use my 24v m35 to jump off of the starter turns much faster???????????

The cnc motor is designed to operate between those voltage ranges. I'm pretty sure those are stepper motors or at least pulse width controlled items though. You're not telling me that you believe all DC motors have to run at their rated maximum outputs at all times unless the voltage is adjusted are you? Voltage adjustment is a very poor way to control the shaft speed of a DC motor.

Your lightbulb test was flawed from your description, I didn't respond to it because it was focused around an incorrect premise.

When you are jumping a 12v starter with a 24v supply, of course it would turn over faster. The starter is made to produce a certain output at a specific voltage and current draw. You're doubling the voltage and it will still try to draw the same amount of current. If you had a 24v starter on your tractor, it would turn over the same as it always did when you tried to jump it off.


edit - is this off topic? Mods, should these posts be moved to another thread?

 

[justinwregier]

If it does turn over then give it a "small" shot of either to see if it starts. If it does then it's almost definitely glowplugs.

I havent gone 12v in my M1009 but Stampy has a point...

I had issues starting/cranking so I put in a new multi gear 24v starter. Next day wouldnt turn over. Imagine the frustration of wrenching and not driving
Hit the air filter with a tiny touch of ether (NOOOO!) and it roared to life.
New Glow Plugs and a relay came next and the M1009 starts every time now.

 

[dmc-4359]

I havent gone 12v in my M1009 but Stampy has a point...

I had issues starting/cranking so I put in a new multi gear 24v starter. Next day wouldnt turn over. Imagine the frustration of wrenching and not driving
Hit the air filter with a tiny touch of ether (NOOOO!) and it roared to life.
New Glow Plugs and a relay came next and the M1009 starts every time now.

You should pick up a DeLorean...I've found it gives the M1009 a Honda like quality by comparison.

 

[ODdave]

dmc.......

EXACTLY AS YOU SAID IT !!!!!!!

"When you are jumping a 12v starter with a 24v supply, of course it would turn over faster. The starter is made to produce a certain output at a specific voltage and current draw. You're doubling the voltage and it will still try to draw the same amount of current. If you had a 24v starter on your tractor, it would turn over the same as it always did when you tried to jump it off."

LIKE I SAID A 24 VOLT STARTER WILL TURN SLOWER WHEN SUPPLIED ONLY 12 VOLTS.
do as you want, preach what you must. i know what my 1028 did when i converted it to 12v. it cranked slower. FYI, all my cables are 0 gauge W/fully soldered lugs and twin 850cca bateries.

 

[dmc-4359]

Perhaps an easier picture can be drawn;

If you were to put a 12v starter into your cucv (without modifying the electrical system), it would turn over much faster than the 24v starter that is currently there.


The issue simply comes down to how the windings in the starter are configured. A starter that is mean to throw down 3.5kw (~5hp) at 24 volts, is configured to draw around 150amps. If you setup a similar dc motor with the intent of using 12 volts, the windings will be configured to draw around 290amps. If you supply that same DC motor with 24 volts instead, it will still work to draw 290 amps...which will double its rated output to 7kw. It can do this for a while but it will burn up sooner because it wasn't meant for that kind of work.


furthering that;

Say instead of a DC motor type starter that was rated at 3.5kw. What if we simply had a tiny steam engine that generated the requisite 4-5hp of gear spinning power? Would it be reasonable to claim that it must turn even slower because there are no volts at all?

 

[dedgar301]

I live about 5 or 10 mins from you. I live near Heritage Hills. If you are still having issues with your 1028, let me know and I'll come over and see if I can shed any light on the subject. I had my truck for about 3 years now and have run into most of the problems everyone else has had (alt lights, no starts, rough starts, smoke, death wobble, trouble starting cold, etc.) I, finally, have my M1028 running smoothly (knock on wood, won't last long I am sure.) Doing a GL pickup this week in Chambersburg (s-250 shelter) but can certainly get with you sometime to help. I love my CUCV. Later, Dan

 

[Warthog]

I live about 5 or 10 mins from you. I live near Heritage Hills. If you are still having issues with your 1028, let me know and I'll come over and see if I can shed any light on the subject. I had my truck for about 3 years now and have run into most of the problems everyone else has had (alt lights, no starts, rough starts, smoke, death wobble, trouble starting cold, etc.) I, finally, have my M1028 running smoothly (knock on wood, won't last long I am sure.) Doing a GL pickup this week in Chambersburg (s-250 shelter) but can certainly get with you sometime to help. I love my CUCV. Later, Dan

I don't think you will get a response from him.

This thread is a year and a half old and he hasn't signed on since April 2010.

 

[Swede]

I am always around .. I also do alot in guest form. Sorry Im not active been Insanely busy!! Life has agreat way of kicking you when you have already been kicked!!!!!!!!!!!!

 

[idM1028]

Hold on. You said you bled the air out of the fuel system. Did the starter turn when you tried to start it, did it make a clicking noise, or did it just do nothing? If it made a clicking noise, your batteries are about dead. If it did nothing, but the starter bench tested as being fine, its VERY dead batteries or something in the circuit. If the starter turned, but the engine didn't fire (and you did a fuel filter change or bled the system or both) chances are, it just needs a little bit more persuasion to get the engine started. I've done filter changes (and bled the system) and d*** well near killed my batteries trying to get the truck started. I think next time I do a filter change, I'm going to put a small plastic hose in the filter and prime it with diesel before I bleed it.