Reed Schulze 0 #1 Posted yesterday at 12:46 PM Hey everyone, Im very new to the wheel horse family and noticed my mower was slowly dying. After doing some digging, I saw the rectifier isn’t producing the voltage I need. I’ve been trying to look up rectifiers but the only ones I’ve found that match my shape are the John Deere Onan P-series 20. Can I use this on my wheel horse? Anyone else tried it with success? Found a few on Amazon. Thanks in advance! Share this post Link to post Share on other sites
ri702bill 12,836 #2 Posted yesterday at 04:23 PM Welcome! Before purchasing a replacement - take the time to remove the mounting fasteners, CLEAN all involved - the mounting on the tractor, the back & front mount areas of the rectifier & the fasteners. Why?? The rectified REQUIRES a good ground to work properly. Do that & reassemble - then fire up the tractor to verify battery voltage. Many of us run a dedicated ground wire to the rectifier for that purpose. The failure mode takes place over time as the aluminum oxidized & the other players corrode.... Replacement part needs to be able to deal with amperage of the charging system. Make sure the pin-out & physical connector are the same..... 1 1 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 12,463 #3 Posted yesterday at 07:06 PM If I remember correctly the Onan engines Wheel Horse/Toro used have a charging system rated at 20 amps. Most of the Kohler's have a 15 amp system. You can use a larger rated regulator on a smaller system but not a smaller regulator on a larger system. 1 1 Share this post Link to post Share on other sites
lynnmor 9,013 #4 Posted 22 hours ago Download the Onan Service Manual and follow the instructions for testing the charging system. You can find numerous regulators for the P series Onan on eBay and Amazon. Those cheap parts are working fine for me. The 16, 18 and 20 HP engines are very similar. Share this post Link to post Share on other sites
Handy Don 17,321 #5 Posted 5 hours ago 16 hours ago, lynnmor said: Download the Onan Service Manual and follow the instructions for testing the charging system. You can find numerous regulators for the P series Onan on eBay and Amazon. Those cheap parts are working fine for me. The 16, 18 and 20 HP engines are very similar. This manual is excellent. The gadget is actually a voltage regulator. Yes it does contain a rectifier to convert AC to DC, but it also regulates the output voltage to what the battery needs for charging. Also, it must be connected to a battery, even if that battery is pretty tired, to work properly. Share this post Link to post Share on other sites
