8N Generator rebuild and now possible bad new VR?

1952 8N, 6Volt Positive ground, Side Dist with generator. I had the generator rebuilt last Spring. Generator shop said that my VR was bad, so I bought a new one, installed it and I think I recall it charging once. A-circuit VR, 2-brush externally grounded generator. I keep the tractor on a battery minder at my house when not in use, and I use it only once in a while. I left it down at the family farm for several months, using it for plowing fire breaks and moving some fallen trees, and that's when I realized it was not charging anymore. The ammeter showed about a -10 amp discharge when the lights were turned on, but no charging. I had to jump start it to get it cranked and loaded on a trailer to take home for diagnosis. Generator motored fine (I even posted a YouTube video on how to do that - Thanks for the details souNdguy!) I suspected my VR was bad so I took it back to the generator shop, this time on the tractor along with a brand new VR in the box. They pulled the generator first, checked the repair kit they installed last Spring, and decided to go ahead and rewind the field coils. Put it back together and tested it on the bench and it worked fine. Put it back on the tractor with the "new" regulator I installed back in the Spring and it would not work. At some point they installed the new VR I bought last week and it still did not work. They found the ammeter glowing red. Apparently it was now grounding. Assuming that was bad, they installed a new one and the generator was now putting out 7.4 volts to the battery. At idle. At about mid-throttle it was pumping out around 8.2 volts. At full throttle it was sending 8.6 volts to the battery. I was not there to witness this. They left the tractor running briefly to walk up front and came back to found the tractor had shut off. Tried to crank it and found no fire to the plugs. Traced it back to the coil, which was now ruined. They acquired a new coil and installed it and now it runs. They called me to report that it is ready for pickup and told me the events that I just related here. So I now have a generator/VR combo that will send 8.6 volts to my 6 volt battery, the same combination that fried a working ammeter and coil.

So should I assume that the generator is fine and the new VR is bad?

Should I attempt to modify the VR by bending the tab to decrease the spring tension to lower the max voltage sent to the battery? Or should I cut bait and buy yet another new VR?

And the big question: how much should I expect to pay this generator shop to call this tractor "fixed" based on what I am getting back?

Again, ammeter and coil were working fine before, generator and/or VR were not. Battery is 18 months old.

Thanks,

Jimps in GA.

That is too much juice. Welcome tithe world of cheap regulators. I spent over $300 on regulators in the last couple of years (just because I had the generator rebuilt already). I finally gave up and put an alternator on it. No more problems for the total of $40.

Try another regulator. If you can find someone with a good original one that would be the best option. Good luck - you are going to need it.

Too many people out there representing themselves to be knowledgeable or experts that don't know jack s about what they are doing!!! Tough for the buyer!

reading that was practically a horror story.

Your tractor is not fixed. If they're not going to finish it I would make that a
major point in negotiating what they're planning on charging you.
They will probably argue the ammeter and coil "were on their way out".
They ARE entitled to be paid for the work they did, so be reasonable.
Not too many places will put on a part you brought them anymore.
I would think your genny is fine, VR is bad, and if it were me I would try
adjusting the regulator. Just because you're not out much if you break it
as long as you don't make it worse.
On the other hand, I wouldn't trust it. I'd keep checking the output regularly.
I've got one like that on my 960. I've replaced it twice, and tweaked the last
one several times. Seems like it gets hot and bends on its own. Cheap junk.
It will be solid state this spring.
Sorry to hear about your bad luck. I hope it works out well.

To address your question.....

A 6 volt genny can and will put out more than 6 volts, that's why you need the VR. Not only will the VR if working right keep your battery charged but should allow the genny to put out the needed voltage to have the lgihts on and still charge but not over charge or allow the system to be subjected to too much voltage.

You cannot IMO buy electrical parts from the cheapest supplier. You get what you pay for! Get the cheap ones and you may get 5 or 6 or more before you get a good one! Is saving 5 or 10 or even 15 bucks worth the aggravation?

Same thing can happen with an alternator. It can overcharge a system or just plain not work, new right out of the "rebuild" box.

See if your rebuilder can supply you with a VR. If so if there is a problem it's up to them to get it right.

Rick