MTA Not Charging

[Gwiz]

Question: should an MTA continue running if I disconnect either battery cable?

My generator is not charging. I've been through John T's list of checks, but still no luck. I suspect since I just painted the
tractor one piece at a time, I have a bad ground somewhere. However; with a meter, I get voltage/ground everywhere. Generator
motors and slows with the appropriate test. Gauge drops to negative side when I turn on the switch; never goes positive while
running.

When I pull either battery cable; sounds like hitting the kill switch. Is that normal, or further proof of no charging?

Thanks
James

 

[Janicholson]

The voltage regulator is likely not grounded because of new paint. Putting a 8 gauge ground strap from a shiny engine ground, to the regulator mount is likely to work. Jim

 

[rustred]

i read the first question and a diesel does not need power to run. you might have amp gauge backwards.

 

[rustred]

good thing i am getting new glasses. cant even read the title properly.

 

[Janicholson]

We new what you didn't mean. Jim

 

[gene bender]

easy test ground the field post on the gen when engine is running it should charge if it doesent charge the gen is bad are you sure the amp guage is working

 

[gene bender]

Using a meter what is the volt reading on the A terminal when engine is running it should read 7.6v

 

[the tractor vet]

Join the club of no charge on a S/MTA . after YEARS of running my S/MTA on 6 volts and it charging with no problems then getting the hair brain idea i would make the switch to 12 Neg ground and changed the lights to twelve switched the OEM coil to Neg. ground added in a ing resistor and had the org. gen made into a 12 volt with 30 amp charge i have fought this non stop and have done everything to get it to charge and ya know what , it still does not charge unless i remove the cover on the reg. and Force it to , then as long as it running it will charge fine , BUT ONCE you shut down and come back and restart it w2ill not charge till ya Force it to . I have a ground wire from the gen to the reg a ground wire from the reg to the battery ground . One of these days i am just going to make a mount for and alt and stuff that on and be done with it . I just did not want to do that since i am the second owner of this S/MTA and have tried to keep it as much org as possible . I have owned mine now since June 27 1990. She has been showen on Fast line and was in the video of the 1994 Red Power round up .

 

[Charlie M]

You have just described why many of us have given up on generators. In my experience the generators are fine but todays regulators are mostly junk. I've had the same experience with regulators as you describe. If you tap them on the side of the case they start working but eventually they won't work. I have one less than a year old on my BN doing that right now (12 volts) and have a 12 volt generator on my 300U that requires a new regulator about every 4 years. I love the idea of keeping tractors looking original with a generator but if you use the tractor regularly an alternator is a lot more dependable.

 

[BarnyardEngineering]

Removing the battery cable is not a valid test. It is a good way to give you an excuse to get into the wiring on the tractor, once you burn everything up.

Look up "John T's Generator Troubleshooting" on google. There is a step by step procedure out there written by forum member John T that walks you through figuring out what is wrong with your generator charging system.

 

[BarnyardEngineering]

tractor vet, why would you take a perfectly good 6V system and convert to 12V in the worst possible way?

The point of going to 12V is to get rid of the complicated, unreliable generator-regulator setup. Put a simple modern solid state alternator on, and be done with it.

 

[John T]

Heres the link to my Charging Troubleshooting procedure.

https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=ttalk&th=2060825

John T
John Ts Charging Troubleshooting

 

[Janicholson]

Inside the regulator the heavy (cutout) relay is not pulling in. That is what you are pushing to connect it. To fix it just adjust (maybe bend) the contact open limiting tab. This closes the gap between the contacts, maybe .015 to .020 allowing the generators polarized output to exceed the battery voltage, closing the contacts without your finger. If they are too close they stay closed and will let smoke out, so just enough to latch the relay is all allowed. Jim

 

[the tractor vet]

Been there done that , the only thing i have not done is stand on my head turn purple and hold my breath . Plum run out of cuss words even the ones i made up . NOW WHAT ??

 

[Janicholson]

There is a product from one or more suppliers that build an alternator inside a generator body. See link. The other option that is cheaper and easier is a Hitachi 14321 alternator. Jim
Info

 

[Gwiz]

Theres a typo in your directions.
I said I already did that.
Im surprised no one has bothered to read or answer my question. I kept it simple and asked twice.
Thanks
James.

 

[Janicholson]

We read your post. Here are a few questions.
Understand generators do not work at idle. the engine must be 1/4 to 1/3 throttle to make electricity. The tractors were made to work hard, not idle around.
With the tractor shut off, key off, does the amp gauge go to negative 12-15 with the lights on? If no, the lights don't work, fix them.
If the amp gauge moves to the charge side when the situation is as in question #1, the amp gauge is backwards, change all wires from one terminal to the other (battery disconnected before you start doing that)
If the lights do cause the meter to show discharge, it is installed correctly, leave it alone.
If everything is connected as it should be, and the tractor is running at 1/2 throttle, you should see full generator output (charge on the meter) if you put a grounded (to a bare metal spot on the engine block) jumper to the Field post of the generator. If this does not produce charging, the next step is to polarize the field windings in the generator. To do this with it shut off, and ignition off, use a jumper (12gauge solid copper house wire about a foot long, with 1/2 insulation stripped from each end is best) to temporarily connect the Bat terminal on the regulator, to the Arm terminal. It will spark, but is not dangerous. This should be held connected for one second. This polarization puts a magnetic field into the iron of the field poles letting the generator self start. If still no joy, Ground the regulator to that same shiny metal used to make the full field test above. the regulatoe is used to control output, and to do that, it controls the field path to ground. through the body of the regulator. If grounding the regulator makes it charge, clean the metal where it mounts, and the regulator mount as well to shiny metal and it will be fixed. Jim