John c 156 #1 Posted 4 hours ago (edited) I've got what I think may be a rectifier given up 1978 C101 8spd. K241 engine battery not charging when running, 12.65vdc when off 12.50vdc when running 12.35vdc running, headlights on Battery is new in good condition, As close to a manual as I have is one for magnum series Kohlers, based on that I read the following: Neither of the stator leads show shorted or grounded, about 2~3 ohms between them, and 34ish-vac output at full throttle. So I suspect the rectifier is at fault is there a chart showing points to test and values to expect to troubleshoot the rectifier ? I've got others laying around, so how interchangeable are they among other sizes engines Also how can you determine what amperage the stator is rated for ? Thanks, john Edited 4 hours ago by John c Share this post Link to post Share on other sites
ri702bill 12,126 #2 Posted 3 hours ago The rectifier housing must be grounded. Over time, oxidation builds up on the two mounting fasteners. Try jumping the housing to ground (not the fasteners) and retest. If it works, unmount it & clean the mounting area. Some of us add a ground wire between the rectifier housing and the screw head.... A freshly painted surface can cause issues too if the rectifier is attached to it... 1 Share this post Link to post Share on other sites
John c 156 #3 Posted 51 minutes ago OK, I'll try that tomorrow, this old machine has plenty of rust all over it, so this may be something. So is there a way to tell the rating of the alternator ...that doesn't involve taking the flywheel off the engine ? Share this post Link to post Share on other sites
Achto 31,821 #4 Posted 20 minutes ago 27 minutes ago, John c said: So is there a way to tell the rating of the alternator ...that doesn't involve taking the flywheel off the engine ? The spec number on the engine should help get you this information. Share this post Link to post Share on other sites