Moving 3rd brush in Gennie no results

[Jeff/Illinois]

Whether I move the third brush up or down on my 6V generator with a diode cut out relay, stock Pos. ground, the ammeter still indicates 18-20 amps charge rate at fast idle. Original, good ammeter. Generator had a rebuild not long ago.

This is on a spare generator I keep on hand as a back up. Tom W. did a rebuild for me on another generator with his EVR and a stock original cutout and it works A-OK.

Ideas? It's too dang hot to do much out in the garage I tried scoping the generator output with a digital voltmeter (don't have an analog one need to buy one)and it was around 7.2 V but was bouncing too much with the engine running to get a good reading.

I can just run Tom's but I'd like to be sure this one is ready to go as or if I need it someday. Thanks.

I found this doing a search.....

https://www.fordbarn.com/forum/showt...0043&showall=1

[Bob C]

Almost sounds like this thread that the field wires were backwards.
https://www.fordbarn.com/forum/showthread.php?t=223691

Bob

[Rich in Tucson]

I have found quite a few wired for full output all the time, either by mistake or intentionally by the rebuilder. The latter typically have a field and armature wire poking out of the case for an external voltage regulator.

[Rich in Tucson]

Forgot to add, one was on a car driven sporadically over a three year period and showed no ill effects with a 20 amp output but please don't do that.

[Mike V. Florida]

Look at this picture. Three brushes right, ok, two thick and one thin. One thick brush will (should) have a short wire screwed to the cover. It is the brush on the left in the picture.

The other thick one will go to the output terminal of the generator, this one will have additional washers to insulate it from the cover and is on the right in the picture.

The one with the thin brush is the 3rd brush and needs to go to the field windings. It is on the top of the picture.

Remove the cover and check the wiring. Yes it is a pain to open all the brushes to get the cover on but I tilt the cover a little towards one brush and move it with my finger so the brush is on the commutator, then roll the cover to the next brush and move it so the brush is on the commutator keeping the first in place and finally the third.

[Jeff/Illinois]

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Thanks for the replies. It looks like the field wires are backwards. Somehow in my search I missed this thread from June 29th.

Thanks again.

[Tom Wesenberg]

Are the field wires backwards (probably not) or is the field wire connected to the wrong brush?
When the two field wires are backwards, the generator will spin the wrong direction when you polarize it.

[Jeff/Illinois]

Originally Posted by Tom Wesenberg

Are the field wires backwards (probably not) or is the field wire connected to the wrong brush?
When the two field wires are backwards, the generator will spin the wrong direction when you polarize it.

I'll check for how the generator motors tonite or Sat. nite thanks Tom.

[Jeff/Illinois]

Follow up:

I finally found the time to monkey with a generator that wasn't charging and I found that the wire to the second(?) brush the one at 7:00 had a small spot of insulation worn off and it was touching the end plate, going to ground.

Moved the wire a tad, put a very small bit of electrical tape on it, and now we're off to the races. Genny is puttin' out today!!

Thanks for all the tips.

[Mike V. Florida]

Originally Posted by Jeff/Illinois

Follow up:

I finally found the time to monkey with a generator that wasn't charging and I found that the wire to the second(?) brush the one at 7:00 had a small spot of insulation worn off and it was touching the end plate, going to ground.

Moved the wire a tad, put a very small bit of electrical tape on it, and now we're off to the races. Genny is puttin' out today!!

Thanks for all the tips.

Great news!