Working on a 2016 Yamaha Wolverine - Charging system

[ehart814]

Hoping someone here could help me out a bit... @HondaTech ???

Long story short, my cousin has a 2016 Wolverine and after severely overheating it many times, they ruined the top end. Top ring seized in piston...ruined head...melted three sensors. So we rebuilt the top end and it runs perfect now.

Trying to get all the bugs worked out. We rode the other day and he kept having trouble starting it. We had just installed a new battery and tested it to make sure it's good.

He neglected to tell me that his check engine light was coming on and displaying a message "low battery". So I was thinking maybe the stator got cooked when it overheated.

Then he tells me that even before they toasted it, the voltage gauge was running about 12.5-12.8 volts max.

Tested it last night. Key off - voltage is around 12. Yamaha troubleshooting says hold rpms at 5000 and it should read 14 volts. If not 14 volts, replace regulator rectifier. Tested and got 12.5 volts. Lights on, the voltage drops to around 11.8-12 volts. The voltage does rise slightly when rpms increase, but not enough. Have not tested stator yet. Need to unplug and check resistance between the wires.

It appears that the stator is trying to charge, but the voltage is too low. Thinking / hoping it's the regulator/rectifier. Anyone have any advice?

 

[jwfirebird]

like you said more likely the stator, its in the engine and sensitive to overheating, normally when rectifiers go its over voltage

 

[HondaTech]

Assuming it has 3 stator leads, correct?

If so check each lead for short to ground, then check for continuity between each lead as well. If any are shorted to ground or dont gsve continuity to each other the stator is burnt.

You can also check AC output between any 2 or the 3 stator output wires while unplugged from the regulator. While revving the enigne the output between all any 2 pairs should be close.

For instance, we recently had a CBR1000 with a charging issue. Stator output was 60, 60, and 30 volts AC. So we had a dead leg.

 

[ehart814]

Assuming it has 3 stator leads, correct?

If so check each lead for short to ground, then check for continuity between each lead as well. If any are shorted to ground or dont gsve continuity to each other the stator is burnt.

You can also check AC output between any 2 or the 3 stator output wires while unplugged from the regulator. While revving the enigne the output between all any 2 pairs should be close.

For instance, we recently had a CBR1000 with a charging issue. Stator output was 60, 60, and 30 volts AC. So we had a dead leg.

OK awesome! That helps so much. We swapped out the regulator with a used one and nothing changed. It still will make only about 12.1 volts while running down the road. But it does charge enough to stay running. Last weekend he went for a ride at night. Went about 7 or 8 miles and the headlights were still on when he came back. So it is charging a little, just not enough.

Yes, there are 3 stator output wires and I know right where the plugs are...

We are also going to double check the battery, even though we just put a new battery in. Those wolverines just take a lawnmower battery! They don't last quite as long, but wayyyy cheaper to replace and available anywhere.

 

[jwfirebird]

yamaha has the cheapest maintenance by far, the oil changes are car filter for a couple bucks, diffs are truck diff oil and standard atv oil, use to get everything at walmart for about 20 bucks

 

[ehart814]

So back on this again... Last night I unplugged the stator wires. Tested between each of the legs. The resistance was the same between them all, none of them shorted to ground. Started engine and checked AC voltage between each leg. Same voltage between the three. Held engine at higher rpm. Checked voltage again - same between all three legs. It all seems to check out... Is it possible for all three legs of the stator to be equally weaker than they should be? Everything is so consistent between the three...

Unhooked all accessories from the battery so only the factory power and ground were connected, just to make sure nothing else is drawing on it. No difference.

Should I suspect the used regulator/rectifier we put in?

 

[jwfirebird]

you verify the ac numbers against the manual numbers, they normally will list a spec

 

[ehart814]

you verify the ac numbers against the manual numbers, they normally will list a spec

The factory service manual only lists the ohm value between the legs. .15-.2 ohm. Each leg shows .1 but i am using a crappy meter. I am borrowing a high quality meter and will re-check

 

[jwfirebird]

the ac value being off is normally the easy way too see if they are about what he posted, its probably not that

 

[ehart814]

Update.

Finally installed a brand new oem stator tonight. Started up. Absolutely no change. Runs right around 12 volts. Hold revs up and it will climb to around 12.1-12.2

WTF

We are very close to being driven insane by this machine


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[ehart814]

At this point, the only thing I can think of is that the regulator/rectifier I swapped is bad. Probably going to try another one. I just can't think of anything else

 

[Russ989]

At this point, the only thing I can think of is that the regulator/rectifier I swapped is bad. Probably going to try another one. I just can't think of anything else

Where are you checking the voltage?

 

[ehart814]

Where are you checking the voltage?

Last night I checked the voltage right at the battery.

Before we replaced the stator, I was checking the voltage everywhere in an attempt to diagnose it. A previous post or two describes what i did.

 

[Russ989]

Last night I checked the voltage right at the battery.

Before we replaced the stator, I was checking the voltage everywhere in an attempt to diagnose it. A previous post or two describes what i did.

Does it have electrical accessories added?

 

[ehart814]

Does it have electrical accessories added?

only a winch and a radio. We have totally unhooked everything and checked. Doesn't seem to be any issues there. Fortunately, it's not a huge mess of wiring and add ons to worry about causing the problem.

 

[Russ989]

only a winch and a radio. We have totally unhooked everything and checked. Doesn't seem to be any issues there. Fortunately, it's not a huge mess of wiring and add ons to worry about causing the problem.

I’d say check the battery cables and check all of the grounds. This really doesn’t make sense.

 

[ehart814]

Might actually run an extra ground as well. Sometimes it’s the simple things.

Can’t believe the stator was good. It got so hot the plastic was melted and really weird looking. Pieces of the plastic insulators were loose in there. It just looked so bad so we thought we finally figured it out. And then it still wasn’t right.


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[JiminAZ]

A bad battery can do this to you with internal short/bad cell/drain. There are a number of ways you can check this:

Way #1:

Pull your battery, put it on a known good charger and see if you can get a full charge on it (12.7 volts resting voltage after charged/charger removed for a couple hours). Leave it rest for a day or so (not connected to anything) and see if it is still holding 12.7v

Way #2 (this is the easiest)

As an alternative you can swap a known good battery in there and see if your problem goes away.

Way #3:

If you can get access to a Hall effect DC amp meter, you can also measure charging amps. With a battery with internal short a lot of amps will be flowing but the battery voltage will not rise accordingly. You have already disconnected all potential parasitic loads, so if a lot of amps are flowing into the battery only, you know you have a bad battery drawing the system down.

The Hall effect DC amp meter that I use is the UNI-T model UT-210E. Bought it for about $37 on ebay. Not the worlds best meter but sufficient for this kind of work (i.e., it ain't no $450 Fluke). Still its a handy little meter great for chasing parasitic current drain.

(Hall effect allows you to measure DC amps using a donut clamp meter rather than putting the meter in the circuit.)

 

[ehart814]

A bad battery can do this to you with internal short/bad cell/drain. There are a number of ways you can check this:

Way #1:

Pull your battery, put it on a known good charger and see if you can get a full charge on it (12.7 volts resting voltage after charged/charger removed for a couple hours). Leave it rest for a day or so (not connected to anything) and see if it is still holding 12.7v

Way #2 (this is the easiest)

As an alternative you can swap a known good battery in there and see if your problem goes away.

Way #3:

If you can get access to a Hall effect DC amp meter, you can also measure charging amps. With a battery with internal short a lot of amps will be flowing but the battery voltage will not rise accordingly. You have already disconnected all potential parasitic loads, so if a lot of amps are flowing into the battery only, you know you have a bad battery drawing the system down.

The Hall effect DC amp meter that I use is the UNI-T model UT-210E. Bought it for about $37 on ebay. Not the worlds best meter but sufficient for this kind of work (i.e., it ain't no $450 Fluke). Still its a handy little meter great for chasing parasitic current drain.

(Hall effect allows you to measure DC amps using a donut clamp meter rather than putting the meter in the circuit.)

New battery was installed at the beginning of the charging mess. First thing we ruled out. Yesterday when I was in the garage testing, the battery read 12.7 volts and I didn't have the trickle charger on it the night before.

Spent some time checking fuses and wiring, swapping relays around, just checking simple stupid stuff. No issues found

 

[JiminAZ]

Whoops! Missed that little factoid in like the third line of your first post.

that is a head scratcher...….

You sort of inferred it in one of the posts but have you compared voltage at the output of the rectifier to voltage at the battery?

I'd sure want to know how many amps are flowing out of that rectifier. Would tell me if it's a voltage regulation problem or a current drain somewhere. You've eliminated almost all potential current drains by disconnecting accessories. Assuming the rectifier is OK that leaves you with some sort of possible crazy current drain into a system that shouldn't draw that much current (say your ignition system or some weirdness with your starter solenoid or something like that).