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Hello I have an Ariens Max Zoom 60 that is about 4 years old. It has the Kohler Courage engine.

I am unable to keep the battery charged. I've replaced the battery the last two years. I have to charge the mower every time before I mow. Once I mow for a little while after charging if I shutoff the blades they will not start again. So it seems something is draining the battery while mowing.

Can anyone give me a place to start? I'm assuming the mower has to have some sort of charging system? I'm handy and don't know alot of electrical but I can usually figure things out with some research and a place to start.

You will need an AC/DC voltmeter to test the charging system and a little understanding of elictrickery.
On the side of the blower housing will be the recti-frier.
It is about 3" x 1.5" and will have a 3 pin plug hanging of it with 2 wires the same colour ( usually yellow ) and another between them a different colour ( usually purple )
There is a 4th wire , usually a flat strap that goes between the body of the recti-fryer and a blower housing mounting bolt.
This is the "big secret" ground connection and generally the strap will be broken or one of the bolts will have fallen out.
I hope this is the case because that is the easiest fix.
I make up a second ground wire to go between the blower housing bolt and the other side of the recti-fryer so there is a back up connection ( Belt & braces approach ).

Now the two outside wires come from the stator and when the engine is running at fast idle ( hare ) each one of those wires has to go from + 12 V through 0 V to - 12 V to allow 12 DC to come out the purple wire.
However in the real world of Elec-Trickery it is not quite so simple and those wires need to be inbetween + 16 V and - 16 V to allow for losses converting to 14 V DC which you need to recharge the battery.
So armed with your new found knowledge start the engine, turn your meter to AC Volts and measure the reading between the two ( same colour ) stator wires.
Somewhere between 30V AC and 40 V AV is good, 28 V AC is just acceptiable and any less is a problem with the alternator.

Now we move on to the recti-fryer.
All those nice AC volts need to be converted to DC volts and if the rectifryer is working properly you should be able to measure 13 V DC to 15 V DC between the purple wire and ground.

Next we need to check all those refreshing DC Volts are getting back to the battery.
So you measure the DC Volts between the battery terminals, tou should get almost the same reading as the DC Voltage between the purple wire & ground.
If not measure the DC volts from the + terminal on the battery and a grounding point on the engine.
If it is significantly higher than the DC Voltage between the battery terminals then the ground (-) lead has a dirty of loose contact point.

Get this far, let us know what you find and we will take you from there.

Ok so my rectifier was a little tricky to find but I finally found it. So I was getting ready to try to start the mower and do as you instructed and measure the two AC leads from the ractifier. But first I thought what the heck I would measure the voltage of the battery. It read 12V, so I assumed the mower would start right away. However, I turned the key and the engine would barely turn. Like the battery was dead. I remeasured the battery after I attempted to start it and it read 10V. So maybe I was off track and it's not the charging system. Maybe I have a different problem altogether?

Does this shed any new light into the problem? Or should I still hook a charger up to it and get it to start and then measure the ractifier?

If the charging system is not working then the battery will not charge so it will go flat.
A lead acid cell actually is a bit higher than 2 V ( 2.18 V ) so when fully charged with no resistance it in theory goes 2.18 x 6 = 13.08 V.
However in the real world this never happens and when you start pulling big Amps out of a battery the voltage drops like a stone
This is why you actually charge it at 13.5 to 14.5 V
If your generator is only putting out 12 V, it is enough to run the mower but not enough to recharge the battery.
A good charging system will work happily with a bad battery no damage but a bad charging sysetm will destroy a good battery very fast

Ok so I started the engine, put it on fast idle and I measured a steady 27 volts between the two AC wires.

At full speed according to Kohler 28V AC is the cut off.
Two options
Pull the flywheel, clean all connections, make sure the stator coil is making a clean contact with the engine.
Check the wires , they can crack , particularly at the terminal plug or chaff .
reassemble & test again.
or
Replace the stator.
While the flywheel is off clean all the muck out that will have gotten between the magnets.
Sometimes this debris can knock the output down a small amount to the "replace threshold" ( 28 V AC )

Sorry for the delayed response but Ive just recently had the time/money to get this done.

I pulled the flywheel and replaced the stator. I also lightly cleaned the flywheel and then area around the magnets. There was just a little bit of grass and debris. I then reassembled everything. I started it back up and I know get 40v when I measure at the rectifier on fast idle. So I got all excited that I fixed it. I had a battery that was working fine when it was pulled from the same model mower last year. so I put that on and charged it for awhile. I mowed for a little over and hour and then the mower blades quit turning. Which has been a symptom of the low battery. So I had to stop and charge it some more to finish.

Is there anything else I should check? Not sure where to go from here. I'm concerned that I didn't get something back together right but everything else seems to be functioning normally.

lomax0990 said:

Sorry for the delayed response but Ive just recently had the time/money to get this done.

I pulled the flywheel and replaced the stator. I also lightly cleaned the flywheel and then area around the magnets. There was just a little bit of grass and debris. I then reassembled everything. I started it back up and I know get 40v when I measure at the rectifier on fast idle. So I got all excited that I fixed it. I had a battery that was working fine when it was pulled from the same model mower last year. so I put that on and charged it for awhile. I mowed for a little over and hour and then the mower blades quit turning. Which has been a symptom of the low battery. So I had to stop and charge it some more to finish.

Is there anything else I should check? Not sure where to go from here. I'm concerned that I didn't get something back together right but everything else seems to be functioning normally.

Click to expand...

Sounds like our PTO clutch either needs to be adjusted or replaced.
Before you start, are you getting 14 V DC at the battery when the engine is running full speed ?
If not there is a problem with the purple wire from the rectifier to the battery.
Some of the mowers run this through the ignition switch which gave problems and Kohler recommended running it directly to the battery terminal.

Whem running at full speed I was getting a pretty steady reading of 12V. When the blades died after about an hour of mowing I checked again and it was reading 9 volts.

That is way two low so sounds like the rectifier is toast.
Th 40 V AC should got to 20 V DC but in practice you never get it 100%.
The rectifier is mounted in the plastic blower housing and has a thin metal earth strap that goes between one of the blower mount bolts ( ground ) and the mounting bolt of the rectifier to ground out the rectifier.
These regularly break and I usually make up 2 patch wires and ground out both rectifier mounting bolts ( belt & braces approach ) .
Then the purple DC wire goes back to the ignition switch and feeds back into the battery.
Kohler changed the set up latter on so the purple wire goes directly to the battery or to the wire with the fuse on it.
You need to check that the purple wire is feeding 13.5 V to 14,5 V back into the battery when the PTO is running.

Well the first time I took the rectifier off I did not see any strap or any sort of ground connection. I've been looking ever since your first reply for a broken ground connection and haven't been able to find one.

I looked at the engine service manual and found an ignition diagram that doesn't say anything about a ground from the rectifier. I've attached the picture I was looking at from the Kohler service manual. I"ll go back out later and look for a broken strap.

Not sure where to go from here. The purple wire from the rectifier goes into a connector with many other wires. Not sure I should be ripping and tearing into that. I will probably make it worse. (See next paragraph) Should I try to replace the rectifier? Should I Just make up a ground jumper and attach it from the rectifier mount hole to another ground somewhere?

On another note, I managed to snap the flywheel bolt last week with my impact wrench because it had came loose after I hand tightened it when I reassembled it. I gave up and took it to a dealer and asked him to fix that and look at the charging system. When I picked it back up he said "It seemed to be charging, but it may be the rectifier. That is always the first thing to go bad". I didn't get a good feeling that he knew much about the charging system so I just picked it up and hoping I could get it figured out.

The rectifier , item J in the diagram must have an earth ( ground if you like ).
The white wires are the AC in and the Purple wire is the +12 V out but you need a + & a - or electricity can not flow.
In your case item J the rectifier uses the case as both a heat sink and the ground contact.
For this to happen it must be connected to either the battery - or the engine case ( Which is also connected to the battery - )
When new Kohler use a flat steel strap to bridge from a blower housing bolt to the rectifier mounting bolt and because it s flay steel. it breaks very easily .
I make up 2 short wires with ring terminals on both ends and connect both of the recrtifier mounting bolts to a pair of bolts that go into the metal part of the engine.

Well I think i'm almost to the point you tell me I'm out of luck and you've gone as far as you can go But I appreciate your help.

Here is what I did. I made up a quick ground wire using a strand of copper from a leftover piece of 12gauge Romex. I put two ring terminals on the ends and for a quick test attached one end to one of the mounting bolts of the rectifier, and then other directly to the negative battery terminal. Then I measured the volts on the two ring terminals at fast idle and it was a solid 11volts.

Based on my understanding of your previous post I think that's a good test. But again I just know enough to be dangerous.

bertsmobile1,

What do you think about a jumper wire from the rectifier directly to the positive battery terminal? To rule out wiring? If that doesn't work I may try to replace the rectifier.

If you have a ground connection from the body of the rectifier and the purple wire connected to the battery then the purple wire should show battery voltage when the engine is stopped and somewhere between 13 & 14.5 V DC when the engine is running.
THE 2 yellow or white wires supply the AC which will go from + 20 V to - 20 voltswhich is 40 V AC ( can be anywhere from 28 to 40 )
The rectifier uses the bit from 0 V to whatever the furthest is so in this case it would be 0 V to 20 V.
Then there is a resistor or zenner to clip that down to somewhere between the 13 & 14 .5 V required to charge the battery.
Now if you are still getting the 40V AC between the two same colour wires and not getting around 14 V DC between the purple wire & ground then the rectifier is toast.
If you are getting 14V DC between the purple wire and ground but not at the battery then somewhere between the the rectifier & the battery the purple wire has a bad connection.

bertsmobile1,

Just wanted to thank you for your help and let you know that it was solved. Here is a brief summary:

1.) I determined that the bracket that the rectifier is mounted to is grounded, so no strap was required. I verified this by testing the positive battery terminal and grounding it to that mounting plate.

2.) I replaced the rectifier which still didn't do anything, so I determined it had to be wiring with the charging cable from teh rectifier.

3.) I found a different wiring diagram than the one I attached earlier, which clearly showed a fuse in-line with the purple charging cable. Sure enough I traced it out, found the fuse, and it was busted. Replaced the fuse and started getting around 13.5V at the battery.

So I think I had two problems. The stator that I originally replaced, and the fuse. Thanks again for all your help figuring this out.

lomax0990 said:

bertsmobile1,

Just wanted to thank you for your help and let you know that it was solved. Here is a brief summary:

1.) I determined that the bracket that the rectifier is mounted to is grounded, so no strap was required. I verified this by testing the positive battery terminal and grounding it to that mounting plate.

2.) I replaced the rectifier which still didn't do anything, so I determined it had to be wiring with the charging cable from teh rectifier.

3.) I found a different wiring diagram than the one I attached earlier, which clearly showed a fuse in-line with the purple charging cable. Sure enough I traced it out, found the fuse, and it was busted. Replaced the fuse and started getting around 13.5V at the battery.

So I think I had two problems. The stator that I originally replaced, and the fuse. Thanks again for all your help figuring this out.

Click to expand...

It's been six years, so it's a long shot that anyone sees this, but I'll ask anyway: Where is that fuse you replaced? I'm having the same problem, and the wiring diagram clearly shows a second fuse, but I cannot find it on the mower. I asked Ariens. Their suggestion was to take it to the dealer.