muz123 1,191 #1 Posted May 30, 2014 I had a problem where my 520 did not start, so I jumped it and it started. The second I took off the jumpers, it died. Finally (I think) traced it to the Voltage Regulator. Got a knock-off for $19 and put it in. I jumped it and it started and stayed running after jumpers taken off. Measured voltage at battery and got 15.1 Volts. Two days later, just tried to start again and would not start but battery appeared good. Also would not start from other wheel horse. So I finally got it started with truck but when measuring battery voltage, got 5 volts. Should I buy a authentic ONAN Voltage regulator? Thanks Dave Share this post Link to post Share on other sites
Ed Kennell 35,770 #2 Posted May 30, 2014 How old is the battery ? Are you sure it holds a charge ? A bad RR should not keep it from starting or running. 1 Share this post Link to post Share on other sites
muz123 1,191 #3 Posted May 31, 2014 The battery is good but the original RR was starting to come apart. But there may have been another problem as now it starts but when the PTO is engaged everything stops, In the morning I will look at the seat switch. Share this post Link to post Share on other sites
Save Old Iron 1,563 #4 Posted May 31, 2014 try a "poor man's" battery load test voltmeter placed across the battery terminals and crank the engine the voltmeter should not drop below 10 volts at any time during cranking any lower than 10 volts and the battery condition becomes suspect Share this post Link to post Share on other sites
Save Old Iron 1,563 #5 Posted May 31, 2014 Onan vs $20 repro regulators ? Most if not all $20 repro's work fine. You may want to recheck the B+ terminal on the reg once again with the tractor turned in RUN butr the engine not running. You should see battery voltage on the reg B+ terminal. If not, check your wiring from the reg to the ignition switch. Share this post Link to post Share on other sites
muz123 1,191 #6 Posted May 31, 2014 I broke down and purchased an ONAN regulator ($$) and installed it. At first the PTO problem cut everything off, but now it runs great. I think you are correct and the battery needs to replaced. Thanks for your help! Dave Share this post Link to post Share on other sites
cleat 4,984 #7 Posted June 1, 2014 The only thing I have found is the OEM regulator runs at 14 volts and the aftermarket runs at 15 volts in my case. I doubt this is a problem but simply an observation. Cleat Share this post Link to post Share on other sites
Save Old Iron 1,563 #8 Posted June 1, 2014 put the 15 volt RR in a winter tractor higher battery voltage in cold weather is an advantage to keeping the battery in a fully charged state. 2 Share this post Link to post Share on other sites
