MalMac 1,332 #1 Posted December 26, 2011 Ok I have got a buddy that brought home a 520HC. Right off the start he has got a starter that will not disengage after starting the tractor. He is checking the ignition switch and then I told him maybe the flywheel. Looking for some other Ideas hear. I am by no means an expert on the Onans matter of fact I know d*%& little about the Onans. He did fine some wiring that was not right and corrected it according to the wiring diagram. Looking for some help here to pass on to him. Share this post Link to post Share on other sites
TT-(Moderator) 1,162 #2 Posted December 26, 2011 Since it could be either electrical or mechanical, here are my thoughts: The P series Onans use a solenoid-shift starter, so the internal spring should pull the drive gear back away from the ring gear on the flywheel as soon as the power is cut. If that spring is broken or the solenoid on the starter is sticking, the drive gear will not retract immediately. The early models (such as this HC) used an additional relay (the solenoid that looks like one from a Ford product) fastened to the RF corner of the engine mounting plate. If that relay sticks, the starter motor will keep running. A few simple tests with a meter or test light will show if it's electrical-related. Share this post Link to post Share on other sites
MalMac 1,332 #3 Posted December 27, 2011 TT what is the purpose of the additional relay? and did they put them on the newer 520's? Share this post Link to post Share on other sites
TT-(Moderator) 1,162 #4 Posted December 27, 2011 I never dug real deep, but I believe it was used as part of the starter circuit interlock - controlled by the safety switches. (DCL neutral position & parking brake) I had a 1988 or '89 518-H with the "extra" relay, but it was bypassed before I got it. I am pretty sure it was last used in 1989, because it wasn't on my 1990 520-8 or 416-H. Share this post Link to post Share on other sites
MalMac 1,332 #5 Posted December 27, 2011 I was wondering because I did not see it on my 90 or 94 520. My buddy looked on his and it is not there. Starting to think he might have a bad ignition switch. Thanks for the help TT but stay on stand by. This problem he's got here has me stumped if it's not his switch. He just put a new starter on it. Not saying new one are not bad sometimes. Will find out more tomorrow. Thanks again. Share this post Link to post Share on other sites
Shuboxlover 481 #6 Posted December 27, 2011 I had a 89 520-HC that had the extra solenoid.....my 90 520-H and 93 520-H did/does not have them. Share this post Link to post Share on other sites
MalMac 1,332 #7 Posted December 27, 2011 Just exactly where is that extra solenoid located? My friend says he can not find one on his at all and its a 89 HC. TT said it located on the RF of the engine. I am starting to think maybe it was removed. Share this post Link to post Share on other sites
TT-(Moderator) 1,162 #8 Posted December 27, 2011 Click on this link & look for #26. :thumbs2: Share this post Link to post Share on other sites
