520h not charging (all of the sudden)

[Duramax7man7 505]

Have a 520h that I'm working on getting to full functionality. 

 

Engine would occasionally have issues starting. Noticed a red wire behind the battery was rubbed to the wire and corroded. Dropped a nut down behind the steering section. Took the panel off under the steering wheel and gauges and got the nut. Disconnected the 9 pin molex, removed the fuse holder and bracket as well as disconnected the plugs and ground wires from the blade switch. Then fixed the wire by cutting out a 3" section, used heat shrinking wire connectors and then wrapped with electrical tape. Reassembled it all. Engine fired up right away and was fine. 

 Upon finishing up sharpening the blades on the deck. I attached that and went to start the tractor and got nothing but rapid clicks on starter solenoid. Used jumpers, got the tractor started and let her run for a bit and drive it around the yard for a few on full throttle. Shut it down. Tried restarting. Same thing. The ,9 pin molex is in usable shape but I decided to remove and clean up the male metal post on the ignition side of the harness that comes from the voltage regulators middle pin (charging pin I believe). I used fine sand paper t get a mild shine and stuck the end of a tooth pick down the middle of it to give it some strength. Used heat shrink on it before reinstalling it into the molex as the yellow wire was melted a tiny bit and didn't want to risk it. 

 On the engine side of the molex, I cleaned up the inside of the same pins female connector with a tiny piece of rolled up sand paper and blew out well. Thought that it looked good. Reassembled the molex. Got the engine started by jumping and tried to restart after a bit of charging and was fine. Voltage gauge runs around 14v when full throttle. Shut the unit off and went inside. Came back after an hour and no start... 

 What is the main source of not charging on these 520h's. I'm assuming they all eventually experience it. 

[Daddy Don 887]

If it is charging when running and won't start when it is shut down for a while sounds like something is draining your battery while the unit is not running. Look for a wire grounding and draining the battery while it is shut down. Use a volt meter when you shut it down and see what the voltage is. Then before you try to start it check the voltage and see if the voltage is the same when you shut it down. If it is lower then you have a drain on the battery somewhere. The battery may also be weak.

[Duramax7man7 505]

What is the resistance of the Stator supposed to be on this Onan P220G?

[WVHillbilly520H 10,369]

If you found corrosion in 1-2 wires then my guess most are corroded, I cut the Molex out and 1 by 1 replaced each wire connection with "bullet" type connectors and dielectric greased each also, this will eliminate that problem also check the voltage regulator connections for corrosion and clean then use a volt meter to verify that it is truly charging 12+v at idle to 14+/- at WOT also with these 15amp charging systems if the battery is questionable it won't run and charge correctly without a verified good battery, I went through many of these issues this spring, please check out my "Good Friday 520" thread and several others this year on the Onan charging/ intermittent running issues, also if you are having to " jump" around the harness/switch wiring check the "neutral" and PTO safety switches for missing actuators or misalignment,Jeff.

Edited October 13, 2016 by WVHillbilly520H

[953 nut 51,541]

With any electrical problem the first step has to be cleaning and tightening all battery and starter cables including grounds. Also, clean all fuse holders and fuses.    

[cleat 4,936]

If it shows 12 volts with the key on engine off but then jumps to 14 volts with engine running at full speed then it is properly charging.

 

Double check the same way at the battery with a meter and if you get the same thing then it is indeed charging.

 

Charge up the battery then if it still drops off in voltage at the battery when trying to start and the connections are all clean it sounds like a bad battery.

 

Cleat

[Duramax7man7 505]

13 hours ago, WVHillbilly520H said:

If you found corrosion in 1-2 wires then my guess most are corroded, I cut the Molex out and 1 by 1 replaced each wire connection with "bullet" type connectors and dielectric greased each also, this will eliminate that problem also check the voltage regulator connections for corrosion and clean then use a volt meter to verify that it is truly charging 12+v at idle to 14+/- at WOT also with these 15amp charging systems if the battery is questionable it won't run and charge correctly without a verified good battery, I went through many of these issues this spring, please check out my "Good Friday 520" thread and several others this year on the Onan charging/ intermittent running issues, also if you are having to " jump" around the harness/switch wiring check the "neutral" and PTO safety switches for missing actuators or misalignment,Jeff.

 

It was really only wires that were rubbed to the wire and wire was exposed. But, I have been contemplating a new Harness. I did find a post by a member named Save_Iron or something like that who spoke of a type of buss bar. But I also like the idea of yours. I may end up doing that with color coded heat shrink. I got the new battery from Meijer. And it;s the same as the old one. Was that a Mistake? They are 375CA/ 300CCA batteries. I only received one battery with the purchase of these two wheelhorses. so I'm not sure how old it is... Any better batteries out there? I will check that thread out. 

 

 

12 hours ago, 953 nut said:

With any electrical problem the first step has to be cleaning and tightening all battery and starter cables including grounds. Also, clean all fuse holders and fuses.    

 

Everything was working until I pulled the wiring harness out a bit through the front panel under the steering wheel. But I disconnected the molex, blade switch (And grounds that are attached to the bolt that hold the switch bracket) fixed it and pulled it back through. I'm guessing that I disturbed something. 

 

2 hours ago, cleat said:

If it shows 12 volts with the key on engine off but then jumps to 14 volts with engine running at full speed then it is properly charging.

 

Double check the same way at the battery with a meter and if you get the same thing then it is indeed charging.

 

Charge up the battery then if it still drops off in voltage at the battery when trying to start and the connections are all clean it sounds like a bad battery.

 

Cleat

 

I decided to test the stator being that starting was rough and I noticed the flywheel teeth chewed up a bit. So this is what I found. Stator wasn't covered too badly with junk. But the front of the engine was. The Ignition control must be fine as the engine was running. Not sure about the regulator on the shroud though. 

So I tested the stator for continuity and it passed but the ohm reading is 0.... Unless I'm testing it wrong on my Kleins DMM... Here are some photos. I will be replacing the flywheel and maybe at least the starter pinion. The start pinion doesn't look like it matches the flywheel gears very well at all. Someone has obviously messed with this engine as there were a few screws missing from the flywheel screen. And one from the stator. smh...  

 

QUESTIONS:

1. How do I go about testing the Voltage Regulator/ Rectifier?
2. Why am I not getting any ohm reading from the stator if Continuity is fine?

3. Is it common for the flywheel to become this destroyed on an older Onan? (Check out the photos- YIKES!) 

[WVHillbilly520H 10,369]

That's rather rough looking and somewhere along the line a bad oil leak( possibly a loose oil filter) and as far as the the flywheel ring gear I haven't seen anything like on these but on a car it's from starter misalignment, and yes "SAVE OLD IRON" is the guru for electrical testing but there are SEVERAL posts/threads on here about the charging/wiring systems on these Onan powered horses, but in general if the voltage regulator is bad the hour meter doesn't work or it over charges or doesn't charge at all, but using your meter like Cleat said key on engine off 12 volts at idle same or a bit more then WOT 14+/- volts it's working correctly less than 11.5 or more than 14.8 there's something wrong, and if your battery is new and 300CCA that should be good enough, as for the "blade switch" I'm not sure what your talking about since these tractors have a manual maybe your headlights switch? upper left corner in the indicator light panel? Electrical issues not my strong suit I usually blunder through it till I get my end results ,Jeff.

[Duramax7man7 505]

Well I have it torn apart for now like you see it. I started picking some of the dirt off. Not sure if that is all from an oil leak, or just many years of decomposed clippings turned to dirt. that's what is feels like. There is a little cotton in there though too. I'm waiting for parts to rebuild my 1500 psi pressure washer and will be removing most of this crap when I get that together this weekend. I may just pull the engine all of the way off, remove the electrical, shrouds and delicate's, cover holes and give her a good bath. Then I'll be able to see if there's a leak. 

 Blade Switch (PTO switch) ha ha.. Still learning the names, I am... hmmm.

 

 I did look through the wiring diagram of the 1990-1991 520H this afternoon as well as the charging system circuit and checked out a couple of videos about testing the Stator and Rectifier. Though the videos for the rectifier where either with the engine running or for rectifiers with 5 terminals. 

 The stator does produce voltage when passing through a MF. It has continuity between the wires. BUT, it also has continuity from each wire to the metal that the windings are on. I'm guessing this is my issue and that iit may fried the Rectifier. Reason being is that with my (albeit noobie) testing of it, if I use Diode mode on my DMM and place the black lead on the middle terminal and touch the red one to the terminal closest to the Ignition coil, I get a tone (continuity?) both ways (blk lead to middle terminal or red lead to middle terminal). And if I keep the blk lead on the middle terminal and touch the one to the right with the red lead, I get no continuity both ways... I haven't fully looked through the electrical manual yet for my year other than the schematics and circuits. So maybe I'll find a proper rectifier test in there...

 I'm still not sure about the battery being bad either. Going to check with the previous owner and see how old it is. Might be able to get it replaced at the same place as the other being the same one. 

 

 The Headlights to have a bad switch that I can wiggle to get to come on. So that will be replaced. This thing definitely needs some TLC. But I think that she will be really nice one back up to tip top and I can take of her. Then maybe I'll be able to pull apart my 88' Scag 52" walk behind and give some attention to the slight knock coming from the Kaw 14hp 420v... 

I'll report back hopefully by the weekend or post responses...

 

 Thanks so far! You guys are great!

 

   

[Duramax7man7 505]

I took some time and pulled off the Starter to find a 191-1949-04 starter on this 520h. So it's been replaced. I also found a hairline crack at the end of the starter mounting hole on the flywheel side, on the hole next to the cylinder (as opposed to the outside hole). 

It's about 5/8" or so long... I slipped a bolt in there and torqued downward on it to see if it was a weak crack and it didn't budge one bit. I'm not sure if the crack was from the old starter and the flywheel was never changed and just deteriorated over time to this point or what. I'm also still not 100% sure if the starter is okay. I'm going to be pulling it apart tonight or tomorrow and give it a look over. It could have just been a combination of the charging system going and a horrible flywheel.... 

Either way, I contacted boomer and he's sending me a pinion gear, stator and a oil filter air seal, being I didn't have one. That stuff should hopefully get here on Saturday. So a BIG THANKS to him for his time and knowledge! 

 

 

[Duramax7man7 505]

What is the easiest way to remove the retainer ring from the armature to get the pinion gear off?

 

Any suggestions?

Figured it out... I played with it a bit after not finding anything on the net about it. Pushed down on the retaining washer and it popped away from the snap ring, giving access to it. 

So looking at the pinion. It almost looks like one of the previous owners used a file to file down the teeth for better engagement when starting. Unless they come like that. But not sure. 
 But what really becomes evident is the wear pattern (i.e. the shiny part) on the teeth themselves. The pattern looks uneven. Take a look. 

 

 Ntice from left to right in the second (close up) photo. The wear (shiny) is deeper into the teeth on the left and gets shallow on the right? Maybe just a normal thing. Not sure. 

 Really hoping the new flywheel and pinion work well together. As well as the Stator and Rectifier.

Edited October 21, 2016 by Mastiffman

[Duramax7man7 505]

Got the power washer together this weekend and was able to clean up the 520h moderately. Can definitely see the engine and frame better. Was able to get a better look at the engine. Unfortunately when I was taking off the RH side shroud the bolts were brittle and I broke them off in the cylinder head. 

 

 Contacted Boomer again. Hes sending a Head and the bokts along with a small gasket kit for the heads, intake and exhaust manifolds. 

 

Also got the oil filter air seal which I didnt have, a new (used) tested stator and newer starter drice kit in the mail from Boomer as well and he was even kind enough to send the starter repair manual with it. Got that installed in the starter after cleaning it all up. Brushed armature and all. 

 

Photos. 

[bmsgaffer 2,043]

I'm sure you realized this, but be sure to get a new cooling fan for that hydro! You will overheat it when working it if all the blades are broken off. (I have a brand new one I will sell you for $25 shipped if you need one!) I have a bunch of 520 parts I will be listing here soon.

[Duramax7man7 505]

Yes sir. I paid $23 shipped for mine. Slapped it on after it was done drying off. Thanks for mentioning it though. 

Edited October 25, 2016 by Mastiffman

[GMan 82]

Mastiffman,

 

You would do yourself a favor by replacing the gasket behind the oil filter mounting bracket while you have it down that far. The bolts for that bracket are notorious for becoming loose with time and the gasket begins to leak which leaves a condition just like you washed off around the oil filter area. I replace all of mine as the gaskets from Onan have been improved to help alleviate this problem. I also use locktite on the two bolts holding the bracket............................Gary

[Duramax7man7 505]

That can be done. I will check the bolts while Im at it. I was informed that any bolts that could being the crackcase within the oil pressure zone should have teflon thread sealer on them. 

 

Edit: One thing that Id like to note was when I first got this tractor home it had a vey slow oil leak... come to find out it was the oil drain thts was extremely loose. I tightened it back up and theresa not been a leak since. Even after running it. So I will most likely check the bolts when removing the oil filter and go from there. The oil drain wasnt even facing the LH side (when sitting on it). I could easily move the drain pipe. Maybe the source of the leak??? 

Edited October 26, 2016 by Mastiffman

[WVHillbilly520H 10,369]

Yes those Onan oil drain pipes are notorious for loosening up sorry about forgetting to mention that,Jeff.

[Duramax7man7 505]

5 hours ago, WVHillbilly520H said:

Yes those Onan oil drain pipes are notorious for loosening up sorry about forgetting to mention that,Jeff.

 No problem. Yeah I figured that out. Be nice to have someone throw a tack weld on it either side. Don't have anyone local with a welder though. 

 

 Boomer has sent me my new (used and cleanup properly) head with a de-carbonized gasket set. 

Edited October 28, 2016 by Mastiffman

[WVHillbilly520H 10,369]

Sorry can't tack weld the iron pipe to the aluminum oil pan, but some oil resistant thread sealer (ptfe paste) on those pipe threads will help as well as taking off the elbow and screwing it a bit deeper in the pan with the paste thread sealer will usually keep it in place,Jeff.

[Duramax7man7 505]

Oh no, I was referring to the iron pieces themselves. that is what my problem is. When I unscrew the oil drain cap, that main pipe it screws onto is what keeps coming loose unless I clamp a small vise grip on it first. 

[cleat 4,936]

What I do is use liquid teflon on all the joints except the final cap and get them all quite tight.

 

For the final drain cap I just use teflon tape and moderately snug it.

 

When you pull the cap next time, only the cap comes off because the tighter liquid sealed joints do not loosen as easily.

 

[Duramax7man7 505]

That's a good idea. I thought about using something along the lines of a high temp o-ring like on the inside of a female end of garden hose, inside the oil drain cap. 

[cleat 4,936]

Problem is that the cap is a tapered pipe thread.

 

If you got a nipple with a straight cut thread and a cap that seals with a gasket then your idea would be perfect.

[Duramax7man7 505]

Ah gotcha. because of the pipe threading. Makes sense. 

[Duramax7man7 505]

Okay, So I set the tappets, installed the heads and reassembled everything after cleaning most of it. Put the engine back on the tractor,. reinstalled the wiring harness in place, changed the oil and once fuel was flowing she started right up. 

 

Cranking sounds great! No more grinding. At this point.

Checked the charging and it's right where it should be! (Thanks Boomer for the parts!). BUT, after letting it warm up a bit and the running at full throttle and backing off, it backfired out of the exhaust. I'm assuming it's running to rich now after cleaning all of the carbon out?

 

I wanted to reset the main jet screw and see if that helps. Is it the standard 1.5 turns out on this nikki carb? Seems like the only adjust other than the idle speed screw.