TC10284 109 #1 Posted January 10, 2019 I have a 1991 41-20OE02 520-H. I started it up yesterday to let it run a bit. Noticed the voltmeter was showing in the red. Yet it turned over fine and ran fine. Let it idle for about 10min before revving it up. Voltmeter stayed the same whether it was at idle or wide open. Voltmeter appears to be working, as when you shut off the engine, the gauge drops down to below 10v like it should. Connected a voltmeter to the battery terminals and I'm getting a solid 12.5 to 12.6v whether idling or wide open. Is there something wrong with my stator, or wiring? Any way to test to make sure it's charging and engine is not running entirely off the battery? Share this post Link to post Share on other sites
KC9KAS 4,741 #2 Posted January 10, 2019 @TC10284 You should see a voltage around 13.6--14 VDC while the engine is running almost WOT. Share this post Link to post Share on other sites
lynnmor 6,777 #3 Posted January 10, 2019 Didn't you download the manual for previous issues? Here it is: manual As KC9KAS said, voltage is too low if your voltmeter is correct. Possibly voltage regulator, but do the tests. Share this post Link to post Share on other sites
TC10284 109 #4 Posted January 10, 2019 50 minutes ago, lynnmor said: Didn't you download the manual for previous issues? Here it is: manual As KC9KAS said, voltage is too low if your voltmeter is correct. Possibly voltage regulator, but do the tests. Yep, I did. Sorry for asking a question that was probably already answered in that manual. Didn't know if anyone had any other experiences with this issue is all. Share this post Link to post Share on other sites
TC10284 109 #5 Posted January 18, 2019 (edited) On 1/10/2019 at 4:36 PM, lynnmor said: Didn't you download the manual for previous issues? Here it is: manual As KC9KAS said, voltage is too low if your voltmeter is correct. Possibly voltage regulator, but do the tests. OK, I finally had some time (and weather nice enough) to run the tests. On the alternator output test, here are my results: Test 1 - 12.5v battery Test 2 - 11.97v to 12.04v (Step 3 is checking connections and wiring) Test 4: 15v at idle 1800rpm 44v at 3600rpm Additionally, I swapped the regulator rectifier from another 520H and am seeing the same results. I did find one of the main red wires looks like it had a lot of resistance on it, and melted the plastic around it. Pics are here: https://photos.google.com/share/AF1QipMwYVSzPlpS-l_BBgJtB2wq0DxCXKHQYnA0EcOXphKgrDPuQF5D6jPEr5hoJXavwA?key=dTB0LTF4V084YU9FOXA3MnpaVXRwejBXY2l6SGNR I'm at a loss at this point as to what could be causing it. Edited January 18, 2019 by TC10284 Share this post Link to post Share on other sites
lynnmor 6,777 #6 Posted January 19, 2019 That 9 pin connector is toast, temporarily jump a wire around the burnt connector and retest. It might be possible to release the offending terminals and pull them out if they aren't melted too bad. That connector is nothing but trouble for many folks, it isn't corrosion resistant and is something that belongs in the back of a TV. Share this post Link to post Share on other sites
Old 702 4 #7 Posted January 19, 2019 I had a problem like that on a different brand tractor, I just jumped around the bad plug. charges fine now Share this post Link to post Share on other sites
TC10284 109 #8 Posted January 19, 2019 (edited) 27 minutes ago, lynnmor said: That 9 pin connector is toast, temporarily jump a wire around the burnt connector and retest. It might be possible to release the offending terminals and pull them out if they aren't melted too bad. That connector is nothing but trouble for many folks, it isn't corrosion resistant and is something that belongs in the back of a TV. I'll try that most likely tomorrow. I already have replacement connectors, so I guess I can go ahead and swap them out. I did use my voltmeter and connected the B+ on the regulator to the positive on the battery WITHOUT the redwire connected to the terminal and saw 12.79V. Although I don't recall the voltmeter changing to a more normal range. Edited January 19, 2019 by TC10284 Share this post Link to post Share on other sites
TC10284 109 #9 Posted January 26, 2019 I got this fixed. The culprit was a fuse that wasn't fully blown. For some reason, it finally went out when I was messing with it again this evening, and when I put in a new replacement, it showed proper voltage of 13.6 at idle and 14.7 at 3600RPM. My bad luck is that I flipped the switch on another 520H after this one, and it blew the 15A fuse. Yet after replacing it, I still get nothing when I flip the switch. I'm suspecting possible naked wire that was chewed on by mice, but it was getting dark and I didn't have much time to investigate. Share this post Link to post Share on other sites
TC10284 109 #10 Posted January 26, 2019 18 hours ago, TC10284 said: My bad luck is that I flipped the switch on another 520H after this one, and it blew the 15A fuse. Yet after replacing it, I still get nothing when I flip the switch. I'm suspecting possible naked wire that was chewed on by mice, but it was getting dark and I didn't have much time to investigate. Resolved this one as well. It turned out to be the ignition switch was pretty corroded. Cleaned up and it fired up fine. Share this post Link to post Share on other sites
953 nut 51,679 #11 Posted January 27, 2019 2 hours ago, TC10284 said: ignition switch was pretty corroded. Chances are there is a fair amount of corrosion on other connections too. Clean and tighten ALL electrical connections including grounds to avoid future problems 1 Share this post Link to post Share on other sites