Up & Quit

[dwcphoto 7]

Hi Folks,

I did the switch with a 520 rear end in my 518H and it was running great. Very strong. I noticed my voltage meter needle was way to the left, way down, but I mowed with the tractor in heavy grass for probably four hours yesterday. Today I needed the jump battery to start the tractor as the battery was dead. I was able to mow for about an hour and it quit. I used the jump battery to start it but it quit after a minute. Later I was able to start it with the jump battery to get it to the house. It ran for five minutes and quit.

The starter seems fine. Would this be a voltage regulator issue? Any ideas? Thank you very much, dwc

[Sparky-(Admin) 23,277]

It very well could be. The regulator on my 416 (ONAN) just died for no apparant reason last year. They are around $90 new but I scored one from Joe's Outdoor power for $25. Five minute swap and my tractor was charging again.

Mike............

[Save Old Iron 1,571]

Could be a regulator but lets look at the simple things first,

Find the regulator on the engine tins

and check all the connections for corrosion or loose wiring

[dwcphoto 7]

Thanks very much. I'll check these things. I hate to say it, but there could be some corrosion. I'll take a close look at the wiring. By the way, my engine is an Onan 18 hp. thanks, d

[dwcphoto 7]

Hi Guys,

Yep I'm a beginner.... what I thought was the regulator is the solnoid. Where do I find the regulator? Thanks! dwc

[smoreau 658]

Should be in the blower housing of the engine. Most likely the back left of the engine on top of the tins. On older tractors, charging systems need good connections for the charging system to work. After cleaning all the connections, use a dab of dielectric grease to keep the corrosion away.

[WH520 17]

It's right infront of the battery. Make sure to use dialectic grease when putting it back together like stated above. The stuff works great at keeping away corrosion. It's also a good conductor.

[dwcphoto 7]

Thanks very much for all your help. I'll take a look and clean it up before I get a new one. Much appreciated! dwc

[Road-Track 39]

:scratchead:Before you buy a voltage regulator, Check any connections that might have been disturbed when you changed out the rear end.

Also for the voltage regulator to work you need voltage.

I had the same problem with a Kohler. It was connections from the stator on the flywheel that makes the voltage that feeds the voltage regulator. Check to see if you have more than 12V when the motor is running coming into the regulator. If only 12V or less you are just running on the battery and the stator isn't adding power.

Let me know if that makes any sense to you.

Good luck

[dwcphoto 7]

Hi RT,

I'll check those out. I pulled the regulator last night and cleaned it up. It wasn't real bad, but did need a good cleaning. I'm picking up some dielectric grease today and hope to put it back together tomorrow. I'll check that voltage, too. Much appreciated. If I have a question I'll post it quick! best, dwc

[dwcphoto 7]

I reinstalled the cleaned up regulator and it's doing the same thing. I'll check the wires next and see where it leads. Speaking of wires. When I replaced the rear end and put it back together I connected the wire to the gas tank and the wires to the seat/safety switch but there was one that had a male fitting on it that I didn't know where it goes. I don't remember it from before. Does this go somewhere else on the gas tank? Thanks, d

[WH520 17]

That wire should go to the tail lights.

[dwcphoto 7]

Thanks for the response, but I do have the tail lights plugged in. This has a flat male fitting I think. thanks, dwc

[WH520 17]

Hmm, I'm not sure. The only wires I can think of that run to the back are the 2 for the gas gauge and the one for the taillights.

[dwcphoto 7]

Thanks for thinking on it. I'll be taking it apart and looking it over again. Thanks, dwc

[dwcphoto 7]

The wire on top of the solenoid looked like it had been wiggle too many times, so I replaced the fitting on that and will brush it up nicely and put it back together later on. dwc

[stevebo-(Moderator) 8,541]

If you have a volt meter you can confirm if it is the regulator or not. Start the engine and bring the rpm up 3/4 way. Check the voltage going into the voltage regulator and it should be around 28-35 volts depending on the rpm. You can then check the voltage coming out and it should be around 13-14 volts. If it is the same as the battery volts (around 12-12.5 fully charged) then your voltage regulator is bad. I would also "tap" the regulator while testing the volts coming out. It may jump when doing that. Going back to the volts going to the regulator if they are not 28-35 range then you have bigger issues and will have to pull the flywheel to get to the electrical pick up modules behind there. Take a look on ebay under onan 520 now and you will see the various parts listed. I would assume it is your voltage regulator.

I am in the same situation you are right now and in fact need to do this same process on my 520HC as the volt meter is reading 0 and the battery is dead. I just put a charge on the battery and will figure it out today. I hope it is just the voltage regulator. If it is I just gave away my "spare" to a buddy.

[dwcphoto 7]

Stevebo,

Thanks for your help. As you can tell, I'm really new at all this, so this helps a lot. My tractor is actually a 518H, but with a 520 rear end on it. I'll try to take a look at it later this afternoon. Dang work gets in the way... thanks, d

[dwcphoto 7]

Hi,

I spent part of the afternoon sprucing up a variety of wires and plugs. I charged the battery. The tractor starts up nicely and runs fine, but the voltmeter on the dash is still in the yellow. I'm put a voltmeter on the regulator and get no reading at all. I put it on top the coil and I get about 12V. What is the meaning of all this?? thanks! dwc

[dwcphoto 7]

For clarification. On the voltage regulator there are three tabs. Can someone identify what each of these do? Also, if checking the output of the starter/generator should I check that at the regulator or at the starter? When I tried to check with my voltmeter I got no reading from any of the tabs with the meter set on DC, but got identical readings from the left tab and the center tab with the meter set on AC. Thanks very much, dwc

Also, What is the stator and where is that located? Is that the alternator? Thanks, dwc

[dwcphoto 7]

New, aftermarket, regulator is installed and it seems to be working fine. With some sunshine I might get to give it a longer workout this afternoon. Thanks for all your help. dwc

[Kelly 1,033]

Not sure your question was answered, the stator is under the flywheel that is what charges your batt. the two white wires hooked to the reg. go to the stator, your tractor does not have a starter/gen. and the single wire may be a trans temp wire, I know yours is not a 520 but all my 520s have a temp sensor on the right side near the bottom on the trans, it is a single wire.

[dwcphoto 7]

Hi Kelly,

Thanks for your reply. I figured out what that left over wire is and you'll be rolling on the shop floor. It's the second wire to the gas gauge.... You guys are very patience and free with your knowledge! thanks, dwc