Chuck14025 9 #1 Posted May 16, 2022 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. Share this post Link to post Share on other sites
Handy Don 10,439 #2 Posted May 16, 2022 (edited) 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 May 16, 2022 by Handy Don 1 1 Share this post Link to post Share on other sites
Chuck14025 9 #3 Posted May 16, 2022 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. Share this post Link to post Share on other sites
pacer 3,159 #4 Posted May 17, 2022 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. 1 Share this post Link to post Share on other sites
Handy Don 10,439 #5 Posted May 17, 2022 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). Share this post Link to post Share on other sites
Ed Kennell 35,147 #6 Posted May 17, 2022 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. 2 Share this post Link to post Share on other sites
peter lena 7,982 #7 Posted May 17, 2022 @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 Share this post Link to post Share on other sites
Jose 11 #8 Posted June 23, 2022 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? Share this post Link to post Share on other sites
Handy Don 10,439 #9 Posted June 24, 2022 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. Share this post Link to post Share on other sites
Jose 11 #10 Posted June 24, 2022 No I don’t have a manual. 520H model 73501 serial Share this post Link to post Share on other sites
Handy Don 10,439 #11 Posted June 24, 2022 Use This link to search for manuals on the site. Share this post Link to post Share on other sites
Jose 11 #12 Posted June 24, 2022 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 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,444 #13 Posted June 24, 2022 There will be one in the Onan service manual Share this post Link to post Share on other sites