Big Daddy 60 6 #1 Posted February 28, 2021 I have a520h, with a 20hp onan. Does this engine have a voltage regulator,or rectifier, or both? I'm not mechanically inclined. I have a friend who is working on it for me. He wants me to buy a new stator and voltage regulator and/or rectifier. Share this post Link to post Share on other sites
lynnmor 6,773 #2 Posted February 28, 2021 Download the Onan Manual where you will find the proper testing procedures. Throwing expensive and hard to replace parts at it is not the right path. Yes, it does have a combination regulator/rectifier, they can be found cheap on eBay, quality parts are also available from onanparts.com. 5 Share this post Link to post Share on other sites
WVHillbilly520H 10,369 #3 Posted February 28, 2021 1 hour ago, Big Daddy 60 said: I have a520h, with a 20hp onan. Does this engine have a voltage regulator,or rectifier, or both? I'm not mechanically inclined. I have a friend who is working on it for me. He wants me to buy a new stator and voltage regulator and/or rectifier. Not that the stator can't go bad, but its usually highly unlikely, but on the other hand those voltage regulator/rectifiers are a common part that does bad, and not that expensive to replace, I have used these... https://www.ebay.com/itm/New-Voltage-Regulator-Rectifier-For-Onan-Engines-P216-P218-P220-1911748-1912106-/174177362124?_trksid=p2349624.m46890.l49292... So technically not a hard to replace or expensive option to try, but with a cheap multi-meter its not hard to diagnose a charging issue. 2 3 1 Share this post Link to post Share on other sites
Handy Don 10,594 #4 Posted February 28, 2021 (edited) I just went though the same on an Onan P218. It was the $15 voltage regulator. The test sequence in the manual is the way to go. It starts at the likeliest faults easiest to check and moves to the least likely. Skipping ahead may lead to the unnecessary cost and labor of replacing perfectly good parts. (FYI, there is a rectifier built into the voltage regulator.) Last note: DO NOT ever run the engine without a battery correctly connected. The regulator needs it and can be "toasted" quickly without it. This was a common trick on magneto tractors that also had starter/generators but is NOT ok on Onans or other alternator-equipped engines. Good luck. Edited March 2, 2021 by Handy Don 4 1 2 Share this post Link to post Share on other sites
Ed Kennell 35,764 #5 Posted March 1, 2021 Yes , most likely the $15 rectifier or the lack of ground on the old one or a bad connector on a tab. Clean the tabs and Loosen and retighten the screw that holds the rectifier to the tin shroud. 2 4 Share this post Link to post Share on other sites
Big Daddy 60 6 #6 Posted March 1, 2021 Thanks for all your help!! I've always wanted a wheel horse since I was 8 years old. I hope to bring this 520h back to it's former Glory. I'm glad this forum is here, I'm sure I'll be asking more questions later on. Thanks again guys! 6 Share this post Link to post Share on other sites
953 nut 51,650 #7 Posted March 1, 2021 Glad you found us. lots of great helpful people here. 1 Share this post Link to post Share on other sites
peter lena 8,061 #8 Posted March 1, 2021 ED KENNELL, agree with your rectifier grounding detail , also dielectric grease all related mounting points , added a small preforated round hole mounting point for added carb throttle pull point , https://www.google.com/search?q=light+round+hole+perforated+metal&sxsrf=ALeKk02YkzJuXCEeHmSF-o0b4pbg5xN2gw:1614605850532&tbm=isch&source=iu&ictx=1&fir=DwuuC4v8p96MIM%2C7Mhu5DdigTE1fM%2C_&vet=1&usg=AI4_-kSy7kZlpsy94XWKbuqGUSTm1Tke5Q&sa=X&ved=2ahUKEwi297DBm4_vAhVOUt8KHbe-A_oQ9QF6BAgkEAE , grounding was a major start problem I had , went after it at every opportunity , result, instant starts , bright lights , amperage just where it should be . just adding a small , 2" piece of that perforated metal under a mounting point ,give's me a go to spring pull point , pete 1 Share this post Link to post Share on other sites
Ed Kennell 35,764 #9 Posted March 1, 2021 I use the star washers @peter lena. 3 Share this post Link to post Share on other sites
