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I have a Cub Cadet RZT54 with a Kawasaki FR691V 24 HP engine. The mower is not charging the battery as it runs. I have replaced the old battery with a new one, and the problem is still there. I have checked the voltage at the battery, and it's a little under 12 volts with the engine off and the same with the engine running. Turning on the PTO shows a voltage drop on the meter. I would like to try to fix this myself if possible without having to take it to a repair shop. I don't have the skills or tools to tear into the engine, but if there's something I could check externally and replace, I would appreciate any advice or guidance that anyone here can give. Thanks!

This manual should give you the info you need. Section 9 electrical systems for your engine. You can then make a good decision whether you will be able to work on it.

http://www.mymowerparts.com/pdf/Kaw...ASAKI-SERVICE-REPAIR-MANUAL-99924-2093-01.pdf

Thanks so much - That looks like it has the info that I need.

To anyone that can help- I have checked the stator output, and it's around 30V, so I assume that's OK. I also replaced the voltage regulator and bought a new battery. The weather has been bad and I haven't had a chance to mow and see if the battery still discharges while mowing. I still don't get more than about 12.5V at the battery with the engine running full throttle, so I'm thinking the problem may not be solved. One thing- I don't get any lights on the indicator panel when I turn the key on. It does however show the battery voltage, and there is a click from somewhere in the engine when I turn on the key. I read somewhere that the problem could be in the ignition, with current not getting to the battery when running. I'm just about at the end of my rope with this, so any help would be appreciated!!!

12.5 volts at the battery, with a new battery, means it is fully charged. Clicking when you turn the key to the ON position is probably the fuel solenoid opening, which is good. The ignition system has nothing to do with the charging system, so that should not be the problem.

dgossett said:

To anyone that can help- I have checked the stator output, and it's around 30V, so I assume that's OK. I also replaced the voltage regulator and bought a new battery. The weather has been bad and I haven't had a chance to mow and see if the battery still discharges while mowing. I still don't get more than about 12.5V at the battery with the engine running full throttle, so I'm thinking the problem may not be solved. One thing- I don't get any lights on the indicator panel when I turn the key on. It does however show the battery voltage, and there is a click from somewhere in the engine when I turn on the key. I read somewhere that the problem could be in the ignition, with current not getting to the battery when running. I'm just about at the end of my rope with this, so any help would be appreciated!!!

Click to expand...

That manual shows the FR model to NOT have a "voltage regulator" in it, but I know that's not correct as I have the same engine on my Big Dog mower and it has one on it. The FS model on page 9-8 would be more correct however.

In short, you should have AC voltage at the two connections at where AC is shown on the attached page 9-16(pins D & C). There should always be battery voltage to ground on the Pin B. If you do have 30 volts AC coming out of the stator winding and no 12 V DC at pin B, I would guess you have a blown fuse somewhere on your mower keeping the 12V from being there. Check pin B to Ground for the presence of 12V and let us know.

This they call a "voltage regulator", but in reality it is a "Bridge Rectifier" that is made up of 4 diodes in a bridge arrangement to change AC to DC. It must have 4 connections, 2 leads of AC voltage in and Battery & Ground on the other 2 leads of the bridge.
Diode bridge - Wikipedia, the free encyclopedia

Charles

Old Goat said:

This they call a "voltage regulator", but in reality it is a "Bridge Rectifier" that is made up of 4 diodes in a bridge arrangement to change AC to DC. It must have 4 connections, 2 leads of AC voltage in and Battery & Ground on the other 2 leads of the bridge.
Diode bridge - Wikipedia, the free encyclopedia

Charles

Click to expand...

Update to my earlier statement as follows.

After washing my mower after using it for the first time, I hooked up the digital voltmeter to the B pin on the regulator and watched it while running the engine from idle to full throttle. It does seem like there is a "regulation" stage built into this module as the voltage tops out at 14.5 volts about halfway though the rpm's of the engine. This corresponds to an automobile system which does have regulation. A fully charged battery will have 12.8 volts at rest and increase to 14.5 volts with at running rpm's.

Have you checked your voltage at pin B yet? If no voltage there, you have a wiring problem in the mower frame and not an engine trouble. As a test, you can use a jumper wire to connect from the B+ post on the battery to pin B while watching the voltage to ground at that point for varying voltage as I described above.

Charles

Hi Charles- Thanks for all the info. I have installed a new voltage regulator and also a new battery. I checked the voltage yesterday from "pin B" on the regulator when running, and there was around 14 volts being output. I then mowed a little with it (too cold here to mow for long) while watching the voltmeter hooked up to the battery. The battery stayed right around 12v while mowing with the PTO engaged. (Before I replaced the regulator and battery, it would drop quickly when the PTO was engaged.) It started right back up after mowing, so I'm hoping (fingers crossed) that the problem is now fixed with either the new regulator or battery. The only thing that still concerns me is that I've read somewhere online that there should be around 13-14v at the battery when it's running. I'm sure not a mower mechanic and I don't know if that's correct info or not. Thanks for any further advice or info that you can give me. I've learned a lot about mower charging systems already. When this problem first came up, I didn't even know what a "stator" was

Glad I could help. At least you learned how it operates.

Yes, with 14 volts being generated, it sounds like you may be good. Only time will tell for sure.

One good thing you could do when you run it for a full cut, is to check the voltage there after you use it. Like I said a fully charged 12 volt battery should read 12.8 volts after it has sat a while after being charged.

Can't really tell you how much draw that PTO puts on the system as I am not really familiar with that components makeup. Are you referring to a blade engagement circuit coil? I have something like that on my Big Dog, but have not checked its current draw yet.


Let me know how it performs when you get it in regular use.

Charles