Ford 9N generator pegging positive after cleaning connections

[EddieS]

That's a great test to run, Btzj02, and I will definitely do it before taking the generator apart - thanks!! Wish I could get out there now to work on it, but work calls instead. I think I need to retire... ;-)

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[EddieS]

Hi everyone, this is an update from way back in February to the post you can read about above. I finally found the problem with my 8N10000B generator on my 1942 9N and why it was charging full-scale all the time. The insulator on the FIELD terminal is cracked and when I tightened the nut on the FIELD terminal lug, it shorted to the chassis of the generator, causing it to charge full-scale. When I backed off the tightening, it now charges like normal. I had to be very careful with not tightening it much though because the insulator is cracked, which you can kind of see in this picture where I pointed with the arrow.

Question - are there replacement insulators available for the 8N10000B generator? I'd like to replace both the ones on the FIELD and ARM terminals, but I can't seem to find anything online. I may have to 3D print new ones if nothing else!

Thanks,
Eddie

 

[Tall T]

Great, thanks everyone. I will start by re-tracing my steps and measuring continuity to see if there are any shorts. I can't believe I hooked up any of the wires wrong, because I took them off only one at a time, cleaned and re-installed. If I don't find any shorts, then I'll try the re-polarization of the generator.

Quick question - this is more of a theoretical question, but why did Ford put a third terminal on the generator if it's just connected to ground? Why couldn't they get just ground through the chassis and save a third connection?

https://nnalert/howtos/pdfs/Testing-Replacing-Polarizing-8N-Voltage-Regulator.pdf

 

[Jim.ME]

https://nnalert/howtos/pdfs/Testing-Replacing-Polarizing-8N-Voltage-Regulator.pdf

You cannot link that Ford N tractor club on this site, it has been blocked for years.

 

[TheOldHokie]

You cannot link that Ford N tractor club on this site, it has been blocked for years.

Decades

 

[EddieS]

Hi everyone, this is an update from way back in February to the post you can read about above. I finally found the problem with my 8N10000B generator on my 1942 9N and why it was charging full-scale all the time. The insulator on the FIELD terminal is cracked and when I tightened the nut on the FIELD terminal lug, it shorted to the chassis of the generator, causing it to charge full-scale. When I backed off the tightening, it now charges like normal. I had to be very careful with not tightening it much though because the insulator is cracked, which you can kind of see in this picture where I pointed with the arrow.

Question - are there replacement insulators available for the 8N10000B generator? I'd like to replace both the ones on the FIELD and ARM terminals, but I can't seem to find anything online. I may have to 3D print new ones if nothing else!

Thanks,
Eddie

Any thoughts on my post above about if new insulators for the FIELD and ARM terminals are available?

Thanks,
Eddie

 

[Jim.ME]

Any thoughts on my post above about if new insulators for the FIELD and ARM terminals are available?

Thanks,
Eddie

A shop that rebuilds generators and starter should have them.

 

[Tall T]

Big, <DOH ! >
Sorry, forgot about that.
slipped my aging mind!

 

[Dave G9N]

Any thoughts on my post above about if new insulators for the FIELD and ARM terminals are available?

Thanks,
Eddie

You might be able to find an insulating Nylon sleeve washer at the local hardware store. A plain nylon washer on the inside might be needed.

McMaster sells them for under $0.20 each. Too bad they come in bags of 100 plus shipping. Without measuring the screw diameter on my generator, this is just a guess at a combination (#10 screw, 1/4" flat washer) that might fit: https://www.mcmaster.com/91145A239/ flanged washer and https://www.mcmaster.com/95606A430/ flat washer for example. The ID of the flat washer matches the OD of the flanged washer to insulate on the inside too. There are many diameters and lengths available to match the generator wall thickness plus washer thickness. The ones at the store might be too long, but that is not hard to fix.

 

[EddieS]

Just an update on finding new insulators for the FIELD terminal on the 8N10000B generator. After looking everywhere on the internet with no luck, I found a wonderful company called Romaine Electric (https://romaineelectric.com/) that rebuilds old generators and starters and sells parts for them too. Lucky for me they had a location right in my hometown, so I stopped by and got their "Ford generator field kit" for all of $5.46! Had the replacement white insulator I needed for the FIELD post on the outside, but it turns out I also needed to put in the new black fiber washer insulator on the inside of the genny for the FIELD post too to keep it from shorting. After I did that, I put it back together tight and I no longer have any shorted FIELD terminal! Just wanted to put this out there for anyone who might have the same problem and needs to find a source for parts. Thanks all!