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Chuck14025

520H (1995) only charging to 12.5 Volts

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Chuck14025

Where's the alternator? In the starter? Where do I put the test probe to see the voltage it's putting out? 200 donuts to the first one to come up with the right answer.

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Handy Don

The alternator (technically a stator) is behind the flywheel and wired to a voltage regulator affixed to the blower housing above the oil filter,

The two stator wires go on the outer terminals of the regulator and the center terminal has the charging voltage that goes to the battery and the rest of the tractor. At 3,000 rpm, you should see 14.5vdc between that terminal and a good ground or the battery negative.

To work properly, the regulator MUST have a solid ground to its body and it MUST have a decent, partly charged 12v battery connected to the center terminal.

 

NO crispy cremes, please, but an assortment of Dunkin's is always welcome.

Edited by Handy Don
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Chuck14025

Thanks Don, good clear description that's it's actually a stator and which terminals are which on the regulator. I'll start by making sure the grounds and connections are clean. Once charged, the battery does well on a load test. Let you know how I make out when it stops raining. 

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pacer

If the stator is working correctly it will show some high 13v, even getting into 14+. Only showing 12.5v is only reading batt voltage.

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Handy Don
1 hour ago, Chuck14025 said:

Once charged, the battery does well on a load test

This is good news.

 

4 minutes ago, pacer said:

If the stator is working correctly it will show some high 13v, even getting into 14+. Only showing 12.5v is only reading batt voltage.

Good added info.

Stators do fail, of course, but you are absolutely on the right track because it is far more common that connections become corrupted and add resistance to the circuits. Ground connections seem especially prone. In the worst cases, it can cause plastic connectors to become scorched. Electrical resistance ==> heat, right? 

 

The next most likely place to look would be the voltage regulator, and that isn't all that common either (they are readily available and not expensive if it comes to that). Measuring across the two outer terminals at 3000 rpm you should see 30 to even 40 VAC (note the AC).

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Ed Kennell

Check the stator voltage at the two outside lugs on the RR.    It should put out ~ 36 VAC at WOT.    If the stator checks out OK, install a new RR.

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peter lena

@Chuck14025   on your possible grounding issue , just as a try , alligator clip  test wire from battery cable ground bolt to chassis , to your plug in point ground area . any related spot thats ground weak , will not  maintain ground . worth a try , dielectric grease , pete

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Jose
On 5/16/2022 at 6:04 PM, Handy Don said:

The alternator (technically a stator) is behind the flywheel and wired to a voltage regulator affixed to the blower housing above the oil filter,

The two stator wires go on the outer terminals of the regulator and the center terminal has the charging voltage that goes to the battery and the rest of the tractor. At 3,000 rpm, you should see 14.5vdc between that terminal and a good ground or the battery negative.

To work properly, the regulator MUST have a solid ground to its body and it MUST have a decent, partly charged 12v battery connected to the center terminal.

 

NO crispy cremes, please, but an assortment of Dunkin's is always welcome.

Would you have pictures of the Wiring set up on voltage regulator wiring set up? 

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Handy Don
2 hours ago, Jose said:

Would you have pictures of the Wiring set up on voltage regulator wiring set up? 

I am at the show so there are lots of tractors around. I’ll try to get a shot of one. 
Do you have the manuals?  You can also search on this site for threads that mention 520-H and regulator. 

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Jose

No I don’t have a manual. 
520H model 73501 serial 

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Handy Don

Use This link to search for manuals on the site. 

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Jose

Thanks I had already looked at that diagram but that doesn’t help me at all I can’t make any sense of it that’s why I had asked if you can send me a pic I thought you had the same 520 H 20h 

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gwest_ca

There will be one in the Onan service manual

 

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