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Have a Kohler SV710-3036 on a Cub Cadet Z-Force 46 (2011ish?). Battery will not recharge. Went to YouTube University. I think I have an Open Positive. I don't know what that means. Will someone who knows more than I do please educate me on this? Let me ask some questions? Thanks.

according to the IPL this is your votlage regulator/rectifier, takes the A/C from stator, and turns it into the proper DC voltage to charge your battery start the engine and test for DC voltage on the center B+ terminal, you should see greater than your sitting battery voltage, around 13.2-13.5 volts.
You should also have greater than 24v AC on each outside terminal

Scrubcadet10 said:

according to the IPL this is your votlage regulator/rectifier, takes the A/C from stator, and turns it into the proper DC voltage to charge your battery start the engine and test for DC voltage on the center B+ terminal, you should see greater than your sitting battery voltage, around 13.2-13.5 volts.
You should also have greater than 24v AC on each outside terminal
View attachment 67733

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This is where I started my testing but couldn't get any readings off of it which led me to believe there is an open positive. I realized last night in bed that after I unscrewed it from its bracket so I could see it better, it probably was not grounded anymore. Also was reminded that I'm an idiot. Going to have to check it again hooked back up and see where I am then. Bought this mower used. Someone has spliced a bunch of the wires. And not well. Thank you for the response.

I was going to ask was the regulator grounded. In YouTube terms that would be an "Open Negative".

And I hate DIYers hacket jobs on wiring harnesses. I had one back in the Summer that they cut every single wire. It took me few days to splice everything back professionally.

Part of me is tempted to just replace the wiring harness altogether. But I've learned that it's easy for me to get in over my head on things. Step at a time.

OK. Hooked everything back up. Placed red probe on center terminal (B+?) of the rectifier. Black probe on housing of rectifier. No voltage reading. Also tried red on terminal, black on N post of the battery. No reading. Red on P post, black on housing gives battery voltage, 12.7ish. Kohler Engines University channel on YT says if there is no V with center terminal and housing combo, the positive is open. Not sure what that means or what to do about it. Thoughts?

Need to determine why you do not have 12 volts to the B terminal of the regulator. Some are wired through the key switch and it has to be in the run position to get power to the regulator. Can try hooking a wire from the B terminal of the regulator to the positive post of the battery and see what voltage you have with the engine running.

Most of the Z force wiring indicates that ignition needs to be in run to check 12 at B+ terminal of the regulator. Engine has to be running to see if the voltage is above the standing non running battery voltage.

I'll give it a try in the key on position. If I have to start running wires, I'll have to rethink some things. The rectifier is terminal side down and the plug wire is very short. Hard to work in that space. Nice of the engineers to do it that way. Probably get back to it next weekend. Thank you for the suggestions.

Here is an electrical schematic for the Z-Force series.

StarTech said:

Here is an electrical schematic for the Z-Force series.
View attachment 67745

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Thank you.

I’m just an average DiYer but here is my two cents. If necessary charge battery just enough to start tractor then shut motor off.

Use volt meter to check battery DC voltage with engine off. Then start tractor and recheck battery voltage at battery again. It should be higher now indicating voltage regulator is working. (Hi side of 12v to low 13v)??

If regulator is not charging battery, now with engine still running, check AC voltage coming from the engine to voltage regulator. I believe it should be about 24v AC??

If you have the engine sending the correct voltage to the regulator but no voltage increase at battery then you have bad regulator or bad wiring in the regulator circuit to the battery.

The problem here is the regulator and its connection are inaccessible on this particular engine without partial disassembly and the use of a shop made jumper cable for testing.

But usually these regulators do fail over time. Most times a simple test of is it charging test at the starter remote starter solenoid will tell if things are good or not.

One note It is easy to put the charge wire on the wrong solenoid post if it is being changed out.

StarTech said:

The problem here is the regulator and its connection are inaccessible on this particular engine without partial disassembly and the use of a shop made jumper cable for testing.

But usually these regulators do fail over time. Most times a simple test of is it charging test at the starter remote starter solenoid will tell if things are good or not.

One note It is easy to put the charge wire on the wrong solenoid post if it is being changed out.

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I see said the blind man. Like I said, I’m just a home DIY’ er.

This might be why I couldn't get any readings on my multimeter.

Bought a straight from China stator/rectifier/spark plug kit. Also bought a Kohler harness. Stator and flywheel were packed full of debris. Numbers seemed to be good after replacing everything. Won't believe it until the battery stays charged. However, after starting it a number of times, went to take it for a spin since I also replaced the front tires which were beginning to dry rot, and the 20A fuse below the seat blew. And of course, which fuse don't I have? To be continued...

Yelp.. Definitely a failed terminal. Here I would just have replaced the terminal but that is me.

StarTech said:

Yelp.. Definitely a failed terminal. Here I would just have replaced the terminal but that is me.

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I probably should have started there and checked to see if that was the only issue. As I said, easy for me to get in over my head. I like wrenching though and I know enough to get me in trouble. Any thoughts on the fuse? A point in a direction might help me in my research.

Usually these regulators are the 12/15 half wave amp version. So I would fuse at @15 amp.

And yes most DIYers usually go a little over board but that is normal. Just shows lack of experience. Heck many shops do the same thing as they also lack electrical experience and knowledge. But I do have now have 45 yrs of experience doing it so I am little more into the testing stages.

I appreciate people like you taking time to help out. I like learning about how things work. Just don't know enough to know how to troubleshoot nor have enough time under the hood, so to speak, to think to check oddball stuff like broken terminals. Appreciate guys-in-the-know being patient as I work through things. Not enough of that these days.

StarTech said:

Usually these regulators are the 12/15 half wave amp version. So I would fuse at @15 amp.

And yes most DIYers usually go a little over board but that is normal. Just shows lack of experience. Heck many shops do the same thing as they also lack electrical experience and knowledge. But I do have now have 45 yrs of experience doing it so I am little more into the testing stages.

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Have no idea what 12/15 half wave amp means. Did try a 15A and it blew right away.

If it blew the fuse right away you got a dead short somewhere to ground.

First make the PTO is off and then try. The current draw in run position would the fuel solenoid normally which is only a few amps.. If fuse holds then engage the PTO clutch. if the clutch is half way fine then the fuse holds otherwise it will blow the fuse. Note PTO clutches normally pulls less than 7 amps.

Also note that a shorted regulator will blow the fuse as soon as you the the key to run position according the RTZ wiring diagram.

StarTech said:

If it blew the fuse right away you got a dead short somewhere to ground.

First make the PTO is off and then try. The current draw in run position would the fuel solenoid normally which is only a few amps.. If fuse holds then engage the PTO clutch. if the clutch is half way fine then the fuse holds otherwise it will blow the fuse. Note PTO clutches normally pulls less than 7 amps.

Also note that a shorted regulator will blow the fuse as soon as you the the key to run position according the RTZ wiring diagram.

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Just to add that a shorted to ground stator can also cause the fuse to blow because one of the AC terminals on the regulator is bridged to the B+ terminal.

sano888 said:

Appreciate guys-in-the-know being patient as I work through things. Not enough of that these days.

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Yeah there are some cool helpful American guys on this forum and maybe one or two Australians

So I put the fuse in. Started right up. Put the shroud back on, fuse blows. Take the shroud off, change fuse, starts right up. Though maybe one of the bolts was grounding it out or something. Lay the shroud on while running, fuse blows. Figured out that where the carb is connecting to the wiring harness, the connection was being pushed up against the heat shield for the cylinder. Moved the wire, secured it, shroud on, started right up. Always something.

However, with engine running, multimeter is only reading 12.45 at the battery. Got a feeling the recharge problem is not fixed.

Well either way you are making progress even if it is two steps forward and one step back.

Recharging problem depends on the standing battery voltage before starting vs running voltage. If the running voltage is above the standing voltage give it a few minutes to see if it starts climb voltage wise but no more than 14.5 vdc.

And you may still a failed voltage regulator if the stator AC output is within spec. 28 VAC or higher then the stator is fine.

Unplug the wires and do a reading of the two wires from the alternator. Should read @ 28 volts AC at full speed.

StarTech said:

Well either way you are making progress even if it is two steps forward and one step back.

Recharging problem depends on the standing battery voltage before starting vs running voltage. If the running voltage is above the standing voltage give it a few minutes to see if it starts climb voltage wise but no more than 14.5 vdc.

And you may still a failed voltage regulator if the stator AC output is within spec. 28 VAC or higher then the stator is fine.

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Agree. Making progress. At least now I know what's where and can assume that parts are in proper working condition. Glad I got it cleaned out under the flywheel if nothing else. Will start the testing process over at some point. For now, I'll keep charging the battery after each use. Will give updates as I return to this project. Need to move on to pruning. Thank you for the help.

Well, as of yet, I have not had to recharge the battery. Last summer I couldn't go 2 weeks without the battery dying. Having said that, this weekend the mower probably won't start. We shall see. Thanks again for the help.