# Agtronic generator - 1 leg measure 3.3v with its neutral at 120v



## Miab1 (Dec 1, 2020)

I have an ag tronic generator from the 80's with a Briggs and Stratton cast iron 16hp motor. One leg of the 240v is fine measuring 120v but the other leg hot measures 3.3volts and the neutral measures 120v. I measured the diodes at 520 ohms and 478 ohms. The brushes look good and measured 45 ohms across them. All wires look good and are tight. The wires in question are 5 and 7 in the attached diagram.

I am ready to give up on but I am looking for advice on a last effort.


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## Miab1 (Dec 1, 2020)

I watched a video where the guy says there should be continuity between the two yellow (6,8) the 2 black (1,5) and 2 white (3,7). I only have continuity between the 2 yellow. Does that mean windings are fryed?


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## iowagold (Jan 22, 2020)

with a good digital ohm meter like a fluke
click here for the test equipment page
with the gen not running
check the ohms
at 1 to 3
and 5 to 7
report back the numbers you get at those test points


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## Miab1 (Dec 1, 2020)

Thanks for your reply Paul. There is a connector that splits the winding side from the receptacles, diodes, capacitor side. Do I measure the windings side at the connector disconnected?


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## iowagold (Jan 22, 2020)

what you need to check is the stator winding's
plug back in the white plug
with a good digital ohm meter like a fluke
click here for the test equipment page
with the gen not running
check the ohms
at 1 to 3
and 5 to 7
report back the numbers you get at those test points


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## iowagold (Jan 22, 2020)

or check it with the unit all back together
engine off
with an ohm meter 
pin out the 120 vac outlets
hot to neutral for each 120 vac outlet


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## Miab1 (Dec 1, 2020)

Ok, will do it in the morning and report back.


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## iowagold (Jan 22, 2020)

ok cool!


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## Miab1 (Dec 1, 2020)

I get 0.4 ohms on both sets of hot - neutral at the receptacles.


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## iowagold (Jan 22, 2020)

hum
this is going to be a head scratcher!!
do you get the 240 vac when running on the 240 outlet?


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## Miab1 (Dec 1, 2020)

No, I get 120v on one of the hot slots to ground and 3.3v from the other hot to ground.


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## Miab1 (Dec 1, 2020)

When I tested the diodes they were still screwed into the aluminum housing but disconnected on the lead in. Was that ok? They seemed to test fine. 

Also, I didn't test the capacitor because I figured one leg was reading 120v so it should be ok. Otherwise I wouldn't be getting voltage on either leg if it was bad right ?


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## iowagold (Jan 22, 2020)

so what is the reading on the 240 outlet?
L1 to L2


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## Miab1 (Dec 1, 2020)

L1 to L2 is 124v. 120.3v from the one plus 3.5v the other.


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## drmerdp (Apr 10, 2018)

Does it have an AVR or capacitor? I’m assuming capacitor... does it test ok?


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## Miab1 (Dec 1, 2020)

Thank you for your reply. Yes, capacitor. I have not removed and tested the capacitor. I figured because one leg of the 240v is working fine that it should be ok because I would be having issues on both legs.? What do you think?


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## drmerdp (Apr 10, 2018)

Yeah I agree with your thinking, but it’s an easy thing to test in case of some weird anomaly.


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## tabora (Sep 6, 2018)

I know you said you looked at the brushes already, but it sure sounds like a worn-out brush or brush spring or dirty slip-ring? Or a bad stator leg... Which is good, CB1 or CB2?


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## iowagold (Jan 22, 2020)

almost sounds like a hot spot short on the one leg with the low volts of the stator..

with the end cap back off snap some pix of the winding's for us

have you tried a bit of 400 grit or scotch bright on the slip rings yet?
just to break the glaze and 400 grit sand paper on the brushes
and check to make sure they are making good force contact with the slip rings.
and are free in the brush holder....


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