Charging system problems 520H

[zieg72 209]

My voltage gauge is pegged beyond 16V. I have checked the voltage to make sure the gauge is right. The beige wire slip on connector closest to the carb was burnt so I replaced it. I added a ground wire to the case which seemed to work fine for 2 times cutting the grass voltage between 14-14.5. Today I went out and I it back beyond 16V. Pictured is what I got so far. Thanks in advance.

Attached Image (Click thumbnail to expand)

[zieg72 209]

Here is another angle

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[snowbelter 0]

hi i had simalar problems with my 520 lived with it for more than a year i was told it might be the white wiring harness plug turned out to be the voltage regulator

[Sparky-(Admin) 21,403]

Wont "living with it" over charge and kill the battery? I'm thinkin its the voltage regulator myself since you allready gave it a good ground and I think Joes outdoor power has a 520 all parted out on E-bay right now.

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

[Sparky-(Admin) 21,403]

Just scrolled thru all of Joes 520 stuff for auction and there was no voltage regulator.

Mike..........

[dr74go 1]

From what I remember reading, the connector and voltage regulator are the two most common issues with the charging system. You can download the Onan manual from the Toro website. It will tell you how to check all parts of the charging system with a volt meter.

If it is the regulator, search online. You can find aftermarket parts much cheaper if you do a little looking. I had to buy one for mine and it was 1/3 or less the price of Toro.

D.L.

[htopjimmy26 3]

Check the White wire in the 9 pin harness plug I know that mine was burnt badly and wouldn't charge. If the white wire isn.t damaged maybe some other pin in the white 9wire plug is to blame. Good luck :thumbs:

[Save Old Iron 1,566]

Carl,

you might want to go back to the rect / reg assembly again and completely remove the reg from the air shroud. clean the metal on the shroud where the reg sits and clean the area on the reg where you have attached the new ground clip. Double check your new jumper wire too for good connections.

I say this because that is what made an immediate correction to your problem.

Yes, the 520's do have issues with molex connection pins brought on by corrosion and overheating, but that usually causes under - charging and not over voltage conditions.

Over voltage is usually bad regulator ground or a bad regulator. If you remove the regulator from the air shroud, you might find a lot of grass clippings caught on the regulator face causing it to overheat during operation. The back side of the reg is air cooled behind the air shroud.

:thumbs:

[htopjimmy26 3]

I defer to Save Old Iron, he is a valuable resource to us all. :thumbs:

[Save Old Iron 1,566]

Dana,

you do bring up a VERY valid point for all 520 owners to be aware of. I would say sooner or later, the 9 pin Molex connector will cause all types of electrical issues in these tractors.

And please don't forget our friends, the overheated and corroded fuse holders. They can cause all kind of hair pulling problems to solve.

I remember both you and I worked thru some issues with these just last year. :thumbs:

[htopjimmy26 3]

I was just looking and Zeig posted this almost 2 years ago maybe he has already fixed it? Soooo maybe hijacking the thread is ok. I have a snowblower on the front of that 520 now and besides the seat switch (now jumpered) it has been pretty reliable and the power is great. Save, could you recommend a good crimper thats not gigabucks 30-50$. I have sitting in front of me a new 9 pin connector with terminals and a new fuse block courtesy of Eldon. Is there a crimper that will do both terminals?

[zieg72 209]

Yes I got it fixed with an ebay purchase back then. The connections are a problem with the 520's. Delectric grease is essentional on all plugs and fuses. My fuse block already was cooked and inline fuse holders were put in place by the time I got it. A lot of WH fans don't like the ONAN powered tractors because of the cost to fix them. I truely believe they are powerhouses and if you keep the right oil in it and the oil changed at regular intervals and keep the debris out of the rear cylinder cooling fins these ONAN engines will last as good as any Kohler. I haven't heard a horizontal Kohler twin under load but the ONAN sure hunkers down and gets the job done.

[htopjimmy26 3]

The c195s sound almost the same as the 520. The Onan has a little more metallic warble and the Kohler sounds a little more clicky, and true to the hp rating the KT19 feels slightly less powerfull that the P220g.

[Save Old Iron 1,566]

Dana,

Sorry, was not ignoring your request for a good crimper - the post just went off my radar screen.

Let me check. If I'm not mistaken, these terminals are somewhat "heavier duty" than normal molex pins.

Did the bag list a diameter for these pins ? That is what you would need to purchase the proper tool for crimping the wires. Proper crimping is very important for these pins and sockets. If improperly crimped, they will not fit back into the connector shell. Improperly crimped terminals will corrode quicker and may not support higher current flow if all wires are not tightly secured to the terminal.

Honestly, on my 520, I used a 9 pin terminal block -

removed the corresponding set of wires from the 9 pin molex one set at a time - applied a spade crimp connector to each wire - color coded the wire pair with heat shrink tubing and screwed them to the terminal block. A small touch of solder to maintain the contact of wire to crimp connector and I truly do not think this will be a problem for me in the near future.

Bottom line is the Molex connections are NOT really appropriate for high current, long lasting, connections exposed to outdoor elements.

They were most likely an engineering compromise for LOW COST.

[stevebo-(Moderator) 8,351]

:thumbs: but my 520 was not charging at the gauge so I checke the voltage going to the regulator and it was correct 35-42 depending on the rpms so ... I figured it was the regulator and ordered a new one. Changed it out and the same thing. Then the Fireman came over and took a look at it. He chased it down to a blown 30a fuse towards the front of the motor near the starter selinod and that was the issue... Just wanted to chime in so no one else makes the $40 mistake... All good info here guys-thanks!

[htopjimmy26 3]

Thanks for the response Save, No diameters on the terminals but I think that one is 12ga and the other is 14ga but maybe Eldon could chime in as thats where they came from. As far as switching it over to a junction block I have considered it and would prefer to keep it original as possible. If I pack this puppy full of dielectric grease do you think that I will still have probs. in the future?

[Save Old Iron 1,566]

but my 520 was not charging at the gauge

did we change gears here - i thought the original post was for overcharging - are we now not charging at all ?? :banghead:

[Save Old Iron 1,566]

If I pack this puppy full of dielectric grease do you think that I will still have probs. in the future?

Dana,

the main issue with Molex connectors is the loss (over time) of female terminal compression on the male fitting. Corrosion takes place in the voids, large currents thru the partially corroded fittings cause localized heating leading to further expansion and loss of compression in the female fitting. This starts a vicious cycle. Separating the male / female housings only accelerates this deterioration.

Molex connectors are not life long partners ... period.

Dielectric grease will delay the corrosion but not the loss of compression on the female fitting.

[Save Old Iron 1,566]

and folks .....

if you do decide to pack the puppy's full of grease - make sure the grease is DIELECTRIC (non-conductive) grease and not CONDUCTIVE grease like NO_Ox found in an electricians work bag.

I have never used NO-Ox on any sensitive electric connections ( just electrical service entrances for aluminum wiring connects) - but I'm going to guess you don't want it near your 520H engine management connector. :thumbs:

[Kgettys 0]

I need to thankyou guys Ihave a coworker with a 520 with the same problem and after reading this I know right were to look . For payment I got a rear mount tiller for a wheel horse. :omg:

[BaySide1 138]

On 1/5/2010 at 8:23 PM, htopjimmy26 said:

I was just looking and Zeig posted this almost 2 years ago maybe he has already fixed it? Soooo maybe hijacking the thread is ok. I have a snowblower on the front of that 520 now and besides the seat switch (now jumpered) it has been pretty reliable and the power is great. Save, could you recommend a good crimper thats not gigabucks 30-50$. I have sitting in front of me a new 9 pin connector with terminals and a new fuse block courtesy of Eldon. Is there a crimper that will do both terminals?

I have these Snap On Crimpers in my boxes for dealing with Molex Connection pins