416-8 P216G-I Onan Voltage Regulator

[Dave H. 15]

Good Day Folks,

 

I'm stumped.....I hope someone can help.

 

Some short background..........I hope this is not too long.......

 

Having purchased a used "190 hour" 416-8 last week, I've had repeated problems with the original in dash Toro Volt Meter.

 

On intial startup, the volt meter rests just above 12 VDC. After warm up, with the throttle brought to half way, the voltage jumps into the red (16+) and stays there. The first time this occured, I quickly shut the engine down, let her cool off, and then tried a restart. Zilch, Nothing, Nada.......She would not even turn over.

 

I proceeded to conduct a visual inspection of the electrical system and found the 30 AMP fuse welded & melted into the plastic fuse holder. I visited this site and found photos of other people who had this same problem. I considered replacing the fuse block with a new one, just to have my local wheel horse dealer tell me the block was just a piece of plastic and there were no metal connectors provided. The metal inserts for the fuse block were part of the harness, so the block alone would not be enough.

 

My Wheel Horse dealer also told me he doubted the voltage regulator on it's own created this "melt-down". He suggested the problem "could" be prior battery acid had leaked into the fuse block and "ate" or corroded the metal inserts. I suggested I would have him pick the tractor up and let his staff repair the problem. He then asked if all the "Safety Switches" were working. I told him the prior owner had disconnected the Seat, Neutral, and Brake Safety switches, but the circuits were OK. In other words, I had already ruled them out as a potential "Break-In-The-Chain". He stated he would not touch the tractor if the safety's had been defeated. Litigation, Bad Karma or for whatever reasons, he won't touch it. He did suggest checking the ground circuits before purchasing a new voltage regulator. He was happy to sell me a new voltage regulator if needed for 108 bucks.

 

Not too much help from the Dealer......some good advice though.

 

I went back out to the work shop, flipped the fuse holder over to find the 30 Amp and 25 Amp fuse share a common shunt between the two. I inserted an in-line fuse holder between the Red and Dual White outputs keeping the shunt active. I placed new 30, 25 and 15 amp fuses into the system.

 

I then proceeded to go through every ground connection from the engine & frame to behind the dash board. I ran a new ground wire from the ground "bundle" next to the battery direct to the negative lead as well just to rule out a rusty or corrosion problem. I checked the ignition switch and voltage regulator leads and grounds, all good there. I can't think of anything else to check. Wire Brushing, New Bolts and Screws and Contact Cleaner.......I'm ready to test her out.

 

I wheel her out; fire bottle at hand. I turn her over and she starts right up. Sounds Great! As soon as the temperature comes up, the volt meter shoots up to 16+. I won't write what my next words were!

 

I'm out of ideas now. Is it the voltage regulator? Or am I overlooking something else.

 

Sorry this post is so long, but I figured it's better to be detailed then leave something out.

 

Any suggestions? Thanks.

 

 

 

 

 

 

 

[Theroundhousernr 590]

I suggest using a real volt meter to start off with and go from there. Could be an issue with the one on the tractor. Not very accurate to begin with. Over charging generally leads to bad regulator. Either wide open or nothing out of it at all. I installed a twenty dollar one off Amazon in my 520h and have no issues with it.

[Dave H. 15]

I suggest using a real volt meter to start off with and go from there. Could be an issue with the one on the tractor. Not very accurate to begin with. Over charging generally leads to bad regulator. Either wide open or nothing out of it at all. I installed a twenty dollar one off Amazon in my 520h and have no issues with it.

I'm using my Simpson meter. I'm measuring from the battery after a five minute warmup; 1/2 throttle 16.8 volts / 3/4 throttle 20.4. I have not taken it to full throttle. Thanks for the response and help. It's Much Appreciated.

[km3h 543]

Every thing you need to fix the fuse block properly can be purchased here and very cheaply, I might add. http://www.delcity.net/store/ATC-&-ATO-4!way-Stackable-Fuse-Block/p_10898 I recommend you purchase a few extra terminal connectors because they are cheap and nice to have around.

The voltage regulators are sold on EBay very cheaply also.

Use a volt meter and check the voltage directly at the battery. With engine running you should see somewhere around 13.5 volts if your battery is fully charged.

The Onan voltage regulators are on sale at this time on EBay for as little as $20.00 New. Just type Onan Voltage Regulator in the search block.

Edited September 7, 2014 by km3h

[Martin 2,133]

heres the method for testing the regulator from the demystification manual......

 

 

nick posted a source for the fuse block,  terminals and for the regulator.....

 

if you want an oem regulator, it can be bought new here......

 

http://onanparts.com/index.php?main_page=product_info&cPath=1_11&products_id=99

Edited September 7, 2014 by Martin

[Dave H. 15]

Every thing you need to fix the fuse block properly can be purchased here and very cheaply, I might add. http://www.delcity.net/store/ATC-&-ATO-4!way-Stackable-Fuse-Block/p_10898 I recommend you purchase a few extra terminal connectors because they are cheap and nice to have around.

The voltage regulators are sold on EBay very cheaply also.

Use a volt meter and check the voltage directly at the battery. With engine running you should see somewhere around 13.5 volts if your battery is fully charged.

That's a great lead Nick, nice site. In so far as the voltage check, the battery is fully charged. After warmup, I'm getting 20+ VDC to the battery. So I'm assuming the VR is shot.

[Save Old Iron 1,568]

A few quick suggestions.

 

If the case of the voltage regulator loses contact with a negative power rail  (I hate the term ground as that's where I plant my potatoes), regulator DC voltage will rise above normal levels and top out at about half the stator AC voltage.

 

Before replacing the regulator, run a wire between the regulator case and the battery negative (-) terminal. If this does not lower the output from the regulator, replace the regulator assy. Regs off Ebay for $25 - $35 are fine.

 

The melted fuse block is caused by corrosion of the contacts holding the fuses. Corrosion = electrical resistance and electrical resistance with significant power flowing thru it = heat. Of course heat = melted fuse holder.

 

If the fuse contacts become overheated, they loose their ability to maintain a tight connection with the fuse blade. Replacement of the fuse contacts is the only way to cure the loose fit which will lead again to another meltdown.

Edited September 7, 2014 by Save Old Iron

[Dave H. 15]

A few quick suggestions.

 

If the case of the voltage regulator loses contact with a negative power rail  (I hate the term ground as that's where I plant my potatoes), regulator DC voltage will rise above normal levels and top out at about half the stator AC voltage.

 

Before replacing the regulator, run a wire between the regulator case and the battery negative (-) terminal. If this does not lower the output from the regulator, replace the regulator assy. Regs off Ebay for $25 - $35 are fine.

 

The melted fuse block is caused by corrosion of the contacts holding the fuses. Corrosion = electrical resistance and electrical resistance with significant power flowing thru it = heat. Of course heat = melted fuse holder.

 

If the fuse contacts become overheated, they loose their ability to maintain a tight connection with the fuse blade. Replacement of the fuse contacts is the only way to cure the loose fit which will lead again to another meltdown.

Save Old Iron, I'm running out to conduct this check right now......give me a few minutes to report back.............OMG "Where you plant your potatoes"

 

Martin, I'm running the tests off the doc you sent........give me a few...........

[Save Old Iron 1,568]

I suggest using a real volt meter to start off with

I'm guessing this means trust a multimeter more than the on tractor voltmeter.

 

The TORO voltmeters I have tested invariably show too LOW a voltage at the upper range of their measurement.

 

 

 

 

 

Edited September 7, 2014 by Save Old Iron

[Dave H. 15]

A few quick suggestions.

 

If the case of the voltage regulator loses contact with a negative power rail  (I hate the term ground as that's where I plant my potatoes), regulator DC voltage will rise above normal levels and top out at about half the stator AC voltage.

 

Before replacing the regulator, run a wire between the regulator case and the battery negative (-) terminal. If this does not lower the output from the regulator, replace the regulator assy. Regs off Ebay for $25 - $35 are fine.

 

The melted fuse block is caused by corrosion of the contacts holding the fuses. Corrosion = electrical resistance and electrical resistance with significant power flowing thru it = heat. Of course heat = melted fuse holder.

 

If the fuse contacts become overheated, they loose their ability to maintain a tight connection with the fuse blade. Replacement of the fuse contacts is the only way to cure the loose fit which will lead again to another meltdown.

 

 

OK SOI, I ran the negative lead from the regulator case to the negative terminal. At half throttle I'm measuring 18.5 VDC at the battery. The battery is fully charged and I'm measuring with my Simpson meter. (Not the Toro volt meter.) I must conclude the Voltage Regulator is bad and needs replacing. Until a new one is installed, this tractor will be a "Push" mower.

 

I'll check out getting a new fuse holder and relocating it to a place where you can actually get to it.

 

Is there a replacement in-dash volt meter that you folks suggest? Everyone seems to dislike the OEM Toro version. I figure while I'm doing all this wiring work, I might as well upgrade the Voltage meter, Oil Pressure and Engine Temp at the same time. I'll try to get rid of the idiot lights as much as possible.

 

Thanks to all,

 

Dave 

[Save Old Iron 1,568]

agreed on the shorted regulator

 

 

 

 

the TORO voltmeters are OK as long as you realize their limitations - to me, the markings are off. The inaccurate  voltage indications can be mediated by inserting a resistor in line with the meter leads. I thought I did a post on that issue years ago, I'll have to look,

 

 

 

 

 

 

Edited September 8, 2014 by Save Old Iron

[Dave H. 15]

SOI, thanks for the photo explaination. It helps clairify the voltage differentials. The resistor fix is simple and easy. (Just the way I like it.)

 

Many Thanks To All the Responders of this post. What a great group of people!

[Save Old Iron 1,568]

Dave, if you going to rewire your tractor, I might suggest looking into the "MAXI FUSE" style of fuse holder for the 30 amp fuses. These are a holder / fuse combo that are intended for reliable high amperage connections. The fuse actually bolts onto a substantial fuse holder and provides a long term reliable connection.

 

Just as the high current compromises the fuse holder, the 9 pin engine harness connector also suffers from degraded connections on certain pins within the male / female MOLEX connector. You will most likely see evidence of heat stress or aging of the plastic housing on the engine harness connection also. There are several posts which  point out sources to purchase replacement pins and connector shells for this area.

[Dave H. 15]

Good Morning SOI,

 

Thanks for the Maxi Fuse information. Yes indeed, these fuse holders appear to be rock solid and fit for high amp usage.

 

This a great lead SOI. Many Thanks!

 

http://www.bluesea.com/products/5006/MAXI_Fuse_Block_-_30_to_80A

Edited September 8, 2014 by Dave H.