Generator Failures

[Beemon]

 I have a track record of destroying generator armatures. I can't find my third generator at this time to confirm, but essentially what would cause this issue to occur? Incorrect set voltage regulator? Pulley overdrive? 

 

Pulley measures approx. 3.125" outside edge and 1.5" inside v-belt groove.

[Beemon]

Okay, so found my third and most recent generator. Looks like two points on the commutator end are touching. Also some windings at the head of the armature are beat up. It's this maybe debris that got sucked in the back? Can't think of any other reason. 

 

Don't know anyone with a growler, is there a surefire way to check continuity? 

[JohnD1956]

Could one, or both, bearings be worn - allowing the armature to ride cockeyed? 

 

[Beemon]

Bearing in front is nice and tight. Bushing in back also seems good. No scoring on shaft that I can see. No thrown solder either, so no over charging. Looks like it was just some debris. 

 

Went ahead and cleaned up the guts with some electrical cleaner aerosol "for energized equipment". Lots of carbon dust. 

 

I'm going to try and separate those two commutator end pieces and see what happens. 👀 

[ArticiferTom]

Grind the kerf off a 24t hacksaw blade about 2" . Just run lightly between commutators to clear . Do not ply on it .  

  And the wires do not look cross shorted . Just spot re-varnish .

Edited April 17, 2022 by ArticiferTom
Punc. (see edit history)

[Beemon]

Thanks Tom, I did just that. Got it installed and we're in business. Fast idle charging around 14-14.5, which is perfect by the shop manual. Everything seems to be working as normal, looks like those commutator ends were the culprit. Goodbye ugly alternator.