J-D 544 E Alternator/charging puzzle

[melben]

You said it is a new rebuild alternator? Check and see if it self excites after disconnecting the plug, Just had a similar situation on a 2090 Case ag tractor that had the 10SI 3 wire alternator on it, with the SE alternator on and the plug in hooked up it the charge light would be lit constantly and the unit would work and charge normally, the solution for this farmer was to let the charge light/ exciter wire disconnected. See if it starts and charges normally hooked up 1 wire, If the light goes out when the plug is disconnected shut off look at the alternator, don't over complicate things do the simple stuff first

 

[Tony Wells]

melben, this is not a new rebuild as in I just installed it. The tag is dated 9/25/93, so it easily could have many hours on it. This one has the three wire aux plug, which I understand less about than the typical 2 wire aux. All of the terminals are a little loose, so first thing is to remove them from the plastic plug, deox them and bend them tight again. And deox the male side on the alternator itself.

Some have mentioned a relay being involved here. Anyone point out the physical location of it? I'm not there, and won't be for a few days. We have unusually cold and snowy conditions here this week. Supposed to be 0° tonight and we have 8" snow on the ground. Us Texans ain't used to that. I don't plan on leaving my place for a day or three.

 

[melben]

my advice still stands for diagnosis, yes i thought it was a new rebuild but if the light goes out when the plug is unplugged something in the alternator is giving the dash light a path to ground. A others have stated, the light is turned off by voltage equalization, not by a physical switch.

 

[edgephoto]

You most likely have a bad diode.

 

[mg2361]

And I believe that should be enough to extinguish the light

Of course some of this information is serial number dependent so serial number would help with accurate information. If your serial number is over 518774 then there may not be a relay.

Going back to post #15, if the alternator relay is bad your alternator will still charge the battery, the alternator can still "try" to control the light (for lack of a better description), but if the alternator relay is not doing it's job the light on the panel will stay lit. The relay is "wired" in between the alternator and the light (on most 544E's).

 

[Tinkerer]

Awesome info. mg2361.
Not many (me included) would have ever thought that relay would or could be in a charging circuit.
Did JD put them in very many machines ? Like excavators and the agricultural line of equipment.
I have never even (ever) read about them in all the time I have been on HEF.

 

[mg2361]

Did JD put them in very many machines ? Like excavators and the agricultural line of equipment.

I have no idea about the AG end, but no, not many machines had that relay that I can recall. Some of the wheel loaders of that vintage (not even all the "E" series had them) and I think the old 690E excavators. There are probably others, but I'm not sure. My memory is fading.......

 

[Tony Wells]

edgephoto, just for kicks, I will put a scope to the alternator output to see if the waveform shows a diode out in the main rectifier bridge. These are 3 phase alternators I believe, so it should show easily. Otherwise I can pull the alternator and check each individually. Back in the old days, we used to replace diodes when they went bad. We didn't automatically replace the entire alternator. I still have a local repair shop I should be able to buy parts from if it comes to that.

mg thanks for that diagram. I'll check and bypass that relay (provided it is used on this machine) if nothing else simple shows up.. It's a good possibility. This machine has been sitting idle (bad trans) for 3-4 years so nothing will surprise me. I don't have the SN here, but in my notebook which I left in it. I'll get it when I go back to the shop.

Thanks all! Several troubleshooting tips have been presented, and appreciated.

 

[edgephoto]

If it is a 10si alternator I would just replace the rectifier bridge myself. I would not replace the whole alternator.

 

[mg2361]

I will put a scope to the alternator output to see if the waveform shows a diode out in the main rectifier bridge.

AC Ripple should not exceed 500mV at 1500 rpm with lights and accessories on.

 

[Tony Wells]

AC Ripple should not exceed 500mV at 1500 rpm with lights and accessories on.

I agree, and of course, could put an external diode/rectifier as a bandaid, but I'm not too keen on that approach. I'd replace the bridge first.

 

[hookedondiesel]

I agree, while your at it, replace the voltage regulator....and make sure your scope is calibrated properly, (OOT). Hopefully you've checked your negative and positive cable's for resistance,...and voltage drop's, what am I thinking, of course you have. I'm wondering if the ozone may have some effect on your dilemma. Perhaps alternator belt integrity or tire pressure. Who know's...In any event, please let us know what you deduce.

 

[Tony Wells]

Ok, back to this for a little while.

This is my relay board. Naturally no labels of any sort and no documentation. So I have to trace the charge circuit down to see which relay controls the light, assuming this one even uses a relay. Sure wish it wasn’t so tough for us aftermarket guys to get paperwork on stuff like this. The OEM’s have to know there are a bunch of us out here, and bring a free economy, we’re not going anywhere. And in cases like this, surely there aren’t so many units being worked on that the failure to call out a dealer tech would really cost them. Just a control issue to keep just anyone from working on this stuff and making mistakes that could cost lots of money, damage and loss of life or limb that in today’s world would end up being a lawsuit I suppose. Plenty of hungry, less that scrupulous lawyers out there. Maybe I should call Saul.

 

[mg2361]

 

[Tony Wells]

mg2361, thank you for that. This is my main Monday project. You'll also notice a very wet pan under all of this. There is a short hydraulic hose that has a pretty steady leak that I want to replace before I start digging around too much in there, but hopefully the colors/numbers are still legible.

Overall this machine is pretty rough and needs some body work, including a new windsheild. Lots of bent up stuff from operators running over things or turning into other machines or trees. We seem to have a problem with some of the trackhoe operators swinging around and clobbering whatever is in the way. But I'm trying to get this one running right at least, and then we have a good fab guy who will straighten or replace the bent stuff, and we seem to have enough work to keep a sandblast and paint guy pretty busy. In the end, it will be a decent machine.

 

[Tony Wells]

mg2361, in your lower left circle, the relay has these wires:

m06 and m06B purple
G10A and G10B Blk
J01 and J02F Tan

That's as close to what you described as I could locate. Nothing close in the other circled items. Other than the J01F you referred to, this looks close to the circuit you wanted to find. All I have is J01, or J02F
Worked in my building today, but let the welders bring a dump trailer (yes, the single hose trailer!) so the could work out of the rain and put some new side plates on. They're going split the single hung end door tomorrow. So there will be two days where the fumes will be some bothersome, besides my own as I try to get a 07 International 8600 cranked. No keys, so spent time today swapping out lock cylinders so I now have keys at least,

So, what can you tell me about that relay?

 

[mg2361]

mg2361, in your lower left circle, the relay has these wires:

m06 and m06B purple
G10A and G10B Blk
J01 and J02F Tan

That would be the alternator relay. I PM'd you.

 

[Tony Wells]

As soon as I get the hosing sorted out and repack a cylinder, I'll be able to run it and see where the current drops out. Or if that relay is bad. I'll post what I find.

Thanks mg, I appreciate the assist. Looks pretty straightforward. Figured it would be, but following the butchers I never know. I don't think this circuit has been tampered with, so it should be simple. And for all those saying it's the alternator, It could be. Just have to do some poking around with a meter, now that I know what I'm looking at. I don't like guessing...it leads to assuming all too often.

t

This is after I get new batteries on a 07 Int'l 8600 that has lost keys. It's in the way, a nice truck, and we need to put it to work or for sale. But I started that project yesterday, so may try to knock it out today.

 

[Tony Wells]

Well once again this project got sidelined. Our Volvo 460 hoe caught fire today. I'll be spending a few days evaluating the damage and making a plan to repair it. The fire started at the feed thru on the head where the injector control harness goes in. Fortunately, the operator noticed it and within a minute or so was on it with the fire extinguisher and minimized the damage. I have another Volvo sitting where it burned from some welders and a lot of oil accumulation. That on may get parted out. The 460, we just put an engine in last year. I may start a thread for posterity's sake on how this goes.

It seems a lot of my projects get "rescheduled" just to help keep operations going. Never a dull moment.