Ford 861 Barn Find, need some help

Morrow

New User
Good afternoon,

Just acquired a sorely needed Ford 861. Have been using an 8n off my family farm for years, works well just slow. Anyways:

Tractor sat in a barn basement for about 8 years
Replaced the battery, plugs, points, water pump, thermostat, fluids, filters and rebuilt the fuel valve (this site showed me how to do that)

It runs perfectly, tons of power, temps great, oil pressure about 40+ at idle. Here is my problem, it does not charge. The 6 volt battery was installed with a negative ground when I acquired the tractor, does not charge at all. My 8n was converted to 12 volt years ago, no experience with generator, not sure how to handle this. First thought was to switch the battery cables, would I fry something? The voltage regulator is probably shot from all the moisture and non use.

Thoughts? Next steps?

Thanks in advance.
 
I would configure it as 6v positive ground as it came from the factory.

You might want to have the generator rebuilt, as long as you did the other work. The regulator might be gummed up some on it.

You need to excite the generator by shorting the proper wire when running the first time, I forget which. The generator remembers, but slowly
loses that memory.....

Paul
 
Thanks, what about the negative ground? This tractor had a positive ground out of the factory, could someone have switched it in the past, still would run but not charge?

It may or may not need a generator rebuild, but if I could get it charging by troubleshooting it, spend my money more slowly as needed if possible.
 
Sorry saw that you said reconfigure it as positive ground and charge the generator. I will do that and let you know.
 
Either way to leave it you need to polarize the generator so it will charge. Good chance the old V.R. is bad due to having sat so long and the points in it corroding
 
Polarize the Gen and see what you get.

Jump bat hot to field.

Then start her up..anything?

If no, while running, jump bat to arm/gen

If that makes charge, cutout is open.

If not, jump bat and gen/arm and field, if no charge, Genny needs rebuilt.
 
Arm is the largest and on back plate. Field is a small one on Genny housing, but it will be run thru an insulating hard rubber or phenolic grommet. If you see a small one just pressed into the housing with no insulating washer, that's just a case ground.
 
Thank you, that is a clear explanation I can understand! Battery is on charge right now will test it after work tomorrow, let you know what I find out.
 
Ps, that test is bad call a full field test that bypasses the regulator.

A test you can do before starting to check Genny I to loosen bolts to let you slip belt off, tighten bolts to get good ground, touch bat hot to arm. A decently Genny should try to spin, perhaps weakly. If yes, or know, jump field and arm to bat hot.. This should make her spin well. If yes, Genny should be good. Most Genny that motor, will charge, most that charge, will motor. Occasionally you can find a Genny with a field fault that will motor, but not charge.

This Moto test properly polarizes the Genny, assuming it is good.
 
I tried polarizing it while on the tractor it did not work. So I pulled the generator, VR and battery brought them home. The generator does motor, the VR was hooked up for years while the battery was negative ground. I have opened the VR, not sure how to test. Now that the battery is hooked up with positive ground the fule gauge is pegged on empty, tank is full was indicating correctly before I switched to positive ground.

Point is I do not know if everything was hooked up right since the prior owner grounded it to negative. Question, how do you check a VR to see if good and is there a 6volt schematic around the site so I can verify?

Thanks
 
Yes you did. Jumping the generator while tractor was running following your instructions I got no charge readings.

I just tried motoring the generator again and it will not move, just sparks. Opened it, bearings on both ends are fine, the brushes are fine, checked the armature for shorts, field coils read about 4 ohms (if I am reading my cheap VOM correctly)

I do not know the next steps. Is the generator bad? I am tempted to convert over to alternator but I like the challenge of figuring this out more. Ground to wet around here to start for the year so I have some time.

Thank you
 
If it wont motor or charge, take it to a rebuilder.
Fault could be in the field, armature or brush connections n holders. Rebuilder can put it on a growler.

Yes, at this point an alt and battery vs a rebuild and vreg is about even $. Brackets are ex, coil n headlamps another 30$
 
Sound guy,

I sorted it out, the gen does motor. I was hooking up wrong the second time. Put on my glasses, inspected the VR, one of the points contact surfaces was half detached, stayed in contact with the other surface then entire time. I assume this is why I could get no spark at the gen while trying to polarize on the tractor. Anyways will pick up a new VR today and put it back together.

Does that sound like the correct course of action?

Thanks
 
if the gen will motor good, then you can charge check it with the vreg completely unwired.

jump arm to battery and field. charge rate should follow rpm. ie.. high rpm makes more charge.

with no vreg, you are running the gen as full field.. so don't do this long.. just to test her.... at max rpm, and full field.. you can get 25-30a out of her.. and be putting 8v on that battery too.
 
You can sell it to me.

There is no way I would fix a 6V system, when a 12V conversion is super simple on that.
 
Update, I had the generator checked it was bad, would motor fine, fiield coils have the correct resistance but would not charge. Turns out the rotor (stator?) was bad, was not worth rebuilding. Switched to an alternator all is good.



Thanks for everyones help.
 

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