Working on a 2016 Yamaha Wolverine - Charging system

[ehart814]

At this point I would think it has to be an issue with the wiring somewhere. This machine has not been all hacked up with a bunch of spliced or tapped wires.

In the shop manual, the troubleshooting goes: battery, reg/rectifier, stator, replace wiring harness. I have done everything up until the wiring harness. Will probably do some more dissassembly to be able to access more of the wiring.

I was suspecting the starter or solenoid could be drawing power but if it was drawing that much I'd think we would see some smoke or smell it.

Keep in mind, this machine was severely overheated. I found a ground wire (8 ga or so) going to the block near the starter that is mounted against the block and the pvc insulation is melted right down around the curve in the casting! The stator is new so the wires coming out of it are new up till where they plug into the harness.

we did check the voltage coming out of the reg/rectifier but I think we should do that again. When we did that, I unplugged the output on it and tested there while it was running. It was hard to get a reading. I hate stabbing wires but do you think it would be better to poke the probe through the insulation of the wire coming out of the rectifier while it's plugged in?

Will probably be spending more time tonight chasing wires, looking for problems. I would think if there was an excessive draw or short somewhere we would blow fuses or catch on fire but we can't find any evidence of a short.

The only other thing that I keep thinking about is the magnets on the flywheel. If one or two fell off somehow, or if they got overheated and weakened, it would cause our problem. I guess if we can't find any other issues, we will consider a new flywheel

 

[Admin]

 

[JiminAZ]

If I were in your situation, I'd invest $40 or so in the DC ammeter I suggested and start chasing where the amps are going. You can do this with everything hooked up and the engine running by just putting the donut around the wire in question. Start at the rectifier and figure how many amps are flowing there. If little to no amps are flowing you can turn your attention to the stator/rectifier arrangement.

If the amps are indeed coming out of the rectifier, see if those amps are showing up at the battery, if there's a "leak" in between you'll know it. Assuming the amps are showing up at the battery check all the branches from the battery to see which direction they are going. Keep working your way through the circuits until you find where the juice is going, hopefully isolating it to a particular wire run and then you can either replace or bypass it.

 

[ehart814]

If I were in your situation, I'd invest $40 or so in the DC ammeter I suggested and start chasing where the amps are going. You can do this with everything hooked up and the engine running by just putting the donut around the wire in question. Start at the rectifier and figure how many amps are flowing there. If little to no amps are flowing you can turn your attention to the stator/rectifier arrangement.

If the amps are indeed coming out of the rectifier, see if those amps are showing up at the battery, if there's a "leak" in between you'll know it. Assuming the amps are showing up at the battery check all the branches from the battery to see which direction they are going. Keep working your way through the circuits until you find where the juice is going, hopefully isolating it to a particular wire run and then you can either replace or bypass it.

Thank you for your help. I just ordered this:
https://www.amazon.com/Multimeter-A...al-Capacitance/dp/B01N014USE/?tag=sxsweb24-20

 

[farmtimpioneer]

@Russ989 did mention all your grounds, I have seen bad grounds do funny things they will send You down rabbit trails, sometime they will look good and even feel tight but corrosion especially on aluminum and combined with the heat that is the perfect storm, You may have already done so but I would physically remove clean and replace every ground engine to frame and battery,,,

 

[JiminAZ]

That meter ought to help you get to the bottom of it. Let us know what you find.

I could see a bad ground to your engine causing this as farmtimpioneer suggests. If the rectifier does not see true ground then its zero reference is off for regulation. You could check regulator output to engine block, then regulator output to battery ground to see if the voltages match. I'm not sure how the rectifier ground is wired so I'm speculating here.

 

[ehart814]

I spent a few minutes last night getting familiar with the new meter... pretty cool to be able to sense current. Didn't have much time to work on the Yami but I did notice a couple things that seemed odd when checking current going through some wires. I"ll report back

 

[ehart814]

We pulled the cover off to inspect the flywheel and magnets. The magnets are strong enough that my pocket knife will stick to them pretty well. We just wanted to see if the magnets are glued to the flywheel like on some engines, but that's not the case. They are somehow held between an inner and outer shell so they are totally captured and can't escape.

Before removing the cover, I spent some time chasing wires looking for a problem. Can't find any problems yet but we are going to have to do some more disassembly to get access to the wiring harness. And of course the harness is totally wrapped up with protective tape that we will have to cut off. This stupid thing is really frustrating. The last couple times we worked on it, we lasted about 15 mins and then just sat down and drank beer because we don't know what else we can do.

 

[ehart814]

Have spent more time on this and haven't gotten anywhere. Did some more disassembly to inspect wiring. Checked continuity of the wires between the stator and reg/rectifier. I replaced the engine ground with a lighter wire and tried starting it. The light wire wouldn't flow enough current to start it, so that rules out the main engine ground wire.

Checked output voltage from the reg/rectifier and found about 12 volts.

Unplugged the stator wires and checked output between each of the legs. Only getting about 6.5 volts AC ????? wtf? Tested each combination of the 3 wires and got 6.3-6.5 Volts AC. How on earth could that be??? The stator is brand new.

Well at this point, we are going to try changing the flywheel to rule out bad magnets. Can't think of anything else to try. Found a used (good?) flywheel on ebay for $70. New is $500

 

[70Bones]

Voltage from the stator should be much higher
For example a 32-amp stator should put out 18 volts AC (VAC) (phase to phase) per each 1000-RPM. At 2000 it should be 36 VAC (18x2). At 3000 RPM it should be 54 VAC (18 X 3). Disconnect the connector to the regulator and just measure the stator.

 

[ehart814]

Voltage from the stator should be much higher
For example a 32-amp stator should put out 18 volts AC (VAC) (phase to phase) per each 1000-RPM. At 2000 it should be 36 VAC (18x2). At 3000 RPM it should be 54 VAC (18 X 3). Disconnect the connector to the regulator and just measure the stator.

Yeah it definitely should be putting out more volts. That's why we suspect the magnets in the flywheel have weakened. It's a brand new Yamaha stator we installed and I double checked everything we did. It's a really easy job to install the stator and there is really no way to screw it up if you put it on the same way you took it off. No clearances to check or anything. It is a bit different of a design though. The stator is bolted to the cover so it comes out when you pull the cover out.

 

[ehart814]

We got the new/used flywheel yesterday. Haven't installed it yet, but there is a huge difference in the strength of the magnets. The magnets in the one he bought are much stronger. It's a very noticeable difference when pulling my pocket knife off of it (very scientific, I know). So I have a little bit of cautious optimism, but we have been let down at every stage of this process so I'm not getting hopes up. We will probably be installing it tonight... fingers crossed!

 

[ehart814]

WE GOT IT! IT WAS THE DAMN MAGNETS IN THE FLYWHEEL!!!!!!!!!!

After all this time and screwing around. Three different reg/rectifiers, new oem stator, hours and hours of checking wires testing fuses and relays and checking grounds.... The problem was the one thing that the Yamaha factory manual doesn't even mention in the troubleshooting!

If I hadn't worked for a magnet company in the past, I wouldn't have known that rare earth magnets get weaker when heated to 300 degrees or more. Due to the design of this flywheel, the magnets had to be rare earth to be strong enough because they are so thin. The magnets in the replacement flywheel were so much stronger than the overheated ones.

I hope Yamaha issues a bulletin for this issue to save others all this headache! Pics to follow

 

[ehart814]

This is the replacement flywheel. You can see the outer shell is thin. The magnets are sandwiched in there. For some reason the first pic of the old flywheel didn’t take. On the old one, that bolt would not stand up like that. You could hardly feel any pull. On the replacement it was more than strong enough to stand on end like this. The old flywheel had a lot of brown/blue discoloring from heat as well.


Sent from my iPhone using Tapatalk

 

[Russ989]

View attachment 185425
View attachment 185426

This is the replacement flywheel. You can see the outer shell is thin. The magnets are sandwiched in there. For some reason the first pic of the old flywheel didn’t take. On the old one, that bolt would not stand up like that. You could hardly feel any pull. On the replacement it was more than strong enough to stand on end like this. The old flywheel had a lot of brown/blue discoloring from heat as well.


Sent from my iPhone using Tapatalk

That’s awesome news! Good job

 

[ehart814]

Now that it's fixed, I sure am glad he didn't take it to a dealer. In the factory book the troubleshooting goes like this: replace battery, replace reg/rectifier, replace stator, replace WIRING HARNESS. If a dealer had it, they would have replaced the whole wiring harness (at great expense) and it still wouldn't be fixed because the book never mentions it as a possible cause of failure to the charging system.

 

[ehart814]

BTW, after spending all this time working on a Wolverine, I think they are a great machine. The only reason this thing blew up was due to abuse and neglect. No fault of the machine at all. Over 4000 miles on it with zero maintenance other than engine oil changes. The air filter had never been checked. We replaced it during the rebuild. The engine could have been saved, but the last time it over heated they just held it wide open and drove it several miles to get home.

So at the current mileage here are all the repairs it has ever had:
New top end and head, all engine sensors replaced (melted)
Charging system
One upper ball joint
left rear axle
left rear wheel bearings
all new brake pads

Not too bad for all those hard miles. I'm impressed by the design and the durability. They have really nice suspension, sufficient power. They have a wet clutch in the engine to prevent excessive belt wear (belts last a LONG time in these). I hope he gets many more miles out of it now that it's fixed. Hopefully no more issues from the overheating

 

[QuadMan747]

Now that it's fixed, I sure am glad he didn't take it to a dealer. In the factory book the troubleshooting goes like this: replace battery, replace reg/rectifier, replace stator, replace WIRING HARNESS. If a dealer had it, they would have replaced the whole wiring harness (at great expense) and it still wouldn't be fixed because the book never mentions it as a possible cause of failure to the charging system.

Why to stay after it, that was a long friggin battle.

Most guys probably would had more beer to forget their troubles and charged it on a charger b4 each ride

 

[ehart814]

Why to stay after it, that was a long friggin battle.

Most guys probably would had more beer to forget their troubles and charged it on a charger b4 each ride

Well he was kinda okay with that but the problem is riding at night because the headlights drain the battery fast, and I the cooling fan doesn't move as much air as it should so it runs hotter. Trust me, we consumed many many beers trying to get this figured out. Maybe I'll take a pic of the dead soldiers before I clean up the mess...

 

[farmtimpioneer]

There's one thing about it now that You have went through what You have been through with that machine at least now You know that machine, Congratulations👍👍

 

[Choogsbro]

WE GOT IT! IT WAS THE DAMN MAGNETS IN THE FLYWHEEL!!!!!!!!!!

After all this time and screwing around. Three different reg/rectifiers, new oem stator, hours and hours of checking wires testing fuses and relays and checking grounds.... The problem was the one thing that the Yamaha factory manual doesn't even mention in the troubleshooting!

If I hadn't worked for a magnet company in the past, I wouldn't have known that rare earth magnets get weaker when heated to 300 degrees or more. Due to the design of this flywheel, the magnets had to be rare earth to be strong enough because they are so thin. The magnets in the replacement flywheel were so much stronger than the overheated ones.

I hope Yamaha issues a bulletin for this issue to save others all this headache! Pics to follow

Awesome news.