Ford 9N Generator No Output

[telmore1964]

About two weeks ago I purchased a 6 volt generator for my Ford 9N from one of the popular auction sites. It was supposed to be tested and service supposedly. Dry bearings were the first thing I noticed and no voltage output was the 2nd thing. I took the generator apart since the seller wouldn't allow returns and I all got from them
was a "oh well I don't know what to tell you". I checked the armature on a growler for shorts and I was able to measure AC voltage on the commutator induced by the growler and measured a little over 7 volts AC. I checked the field and only measured just under 1 ohm on my Simpson 260 which seems to be low to me. I measured equal resistance from the connection between the two coils I would have thought one might be more shorted than the other? I have read a reading of 2 to 3 ohms is more likely. I did get the generator to put out some voltage after working the tractor doing some blading on my gravel driveway. I shut the tractor off for a while then came back to use it again and the generator quit working. This happened two days in a row and I suspect something is heating up (field?)
I was wondering if anyone has run into this issue? We received 7" of new snow today so I got to run the tractor for almost 2 hours doing snow removal in the dark because I wanted to save the battery and not run it down from the headlights. The last thing to try is installing new brushes tis weekend when they arrive.

Thanks
Tom
Anchorage, Alaska

 

[used red MN]

About two weeks ago I purchased a 6 volt generator for my Ford 9N from one of the popular auction sites. It was supposed to be tested and service supposedly. Dry bearings were the first thing I noticed and no voltage output was the 2nd thing. I took the generator apart since the seller wouldn't allow returns and I all got from them
was a "oh well I don't know what to tell you". I checked the armature on a growler for shorts and I was able to measure AC voltage on the commutator induced by the growler and measured a little over 7 volts AC. I checked the field and only measured just under 1 ohm on my Simpson 260 which seems to be low to me. I measured equal resistance from the connection between the two coils I would have thought one might be more shorted than the other? I have read a reading of 2 to 3 ohms is more likely. I did get the generator to put out some voltage after working the tractor doing some blading on my gravel driveway. I shut the tractor off for a while then came back to use it again and the generator quit working. This happened two days in a row and I suspect something is heating up (field?)
I was wondering if anyone has run into this issue? We received 7" of new snow today so I got to run the tractor for almost 2 hours doing snow removal in the dark because I wanted to save the battery and not run it down from the headlights. The last thing to try is installing new brushes tis weekend when they arrive.

Thanks
Tom
Anchorage, Alaska

Hello Tom, welcome to YT! It is interesting to me that you have access to a “growler” armature tester which seems to suggest you have some knowledge about generator charging systems. Yet you have said nothing about your regulator/cutout which can also be a cause of no charge scenario. I am more familiar with Delco style A circuit generator equipped systems, your Ford has B circuit system. I believe there is a way to “motor test” a B circuit generator the same as can be done with an A circuit type. If the generator will motor it usually means it will charge.
Hopefully someone more familiar with Ford “B” circuit systems will chime in to help you.

 

[Powered By IH]

I don't know if the Farmall Cub system is the same but this video could be helpful:

It also might help to polarize the generator, but as to whether that would really help I don't know.

 

[telmore1964]

I figured last night finally it was a brush issue. The positive brush which is grounded to the case of the generator was cracked in two I just couldn't dee it under the screw that holds it place. I replaced that brush and the generator started working again as expected.

 

[Janicholson]

I don't know if the Farmall Cub system is the same but this video could be helpful:

It also might help to polarize the generator, but as to whether that would really help I don't know.

Polarizing a B circuit generator is a good idea, but the process is very different than on an IH. The field is internally grounded so the polarizing voltage must come from disconnecting the Field at the gen and touching the jumper to that F terminal on the Gen. Jim