High DC voltage Question

Hello all,
My 2003 toro commercial ZT mower with Kohler Command Pro 26 EFI burnt up the PTO clutch. I purchased a new clutch but before I engaged it I checked the running voltage at the battery. The voltage was immediatly 14.4v and slowly progressed up to 14.8v at which time I shut it down so as to not fry the ecu unit. Cleaned battery terminals and checked ground connections. Re-started it and the same results. Battery is 3 years old and starts the machine well. Checked battery voltage not running and found 12.4v which I assume is good. All cells were even with water. Decided to replace the regulator/rectifier with OEM Koher part and the voltage does exactly the same thing. Checked the stator AC votage and is normal at about 28v at mid throttle.
The service manual states that the voltage should not go over 14.2v.
I don't want to run the mower with this voltage condition for fear of destroying the new PTO clutch and the ECU.
Any thoughts or recommendations would be greatly appreciated. Don' know what else to do ...:confused2:

I am not sure of the exact model number of your engine but the service manual for the CH26 shows a maximum voltage of 14.7. Sometimes a battery can create weird issue throwing the voltage off. If the voltage doesn't exceed 14.8 on your meter I wouldn't get too concerned since that would be within the accuracy limits of most meters. Where you will get into issues if the voltage gets up around 16 volts or more.

May want to try the test with a different battery if possible. The battery being 3 years old could be starting to get some internal issues causing it to not absorb the current correctly.

ILENGINE said:

I am not sure of the exact model number of your engine but the service manual for the CH26 shows a maximum voltage of 14.7. Sometimes a battery can create weird issue throwing the voltage off. If the voltage doesn't exceed 14.8 on your meter I wouldn't get too concerned since that would be within the accuracy limits of most meters. Where you will get into issues if the voltage gets up around 16 volts or more.

May want to try the test with a different battery if possible. The battery being 3 years old could be starting to get some internal issues causing it to not absorb the current correctly.

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y

Thanks for the rapid reply.

I agree, the battery could be the problem and is definitely worth switching out.
The new PTO clutch from XTremeOPE cautions on the use of the clutch to a maximum of 14.2v. You can understand my concern. Te new rectifier states that it has an overvoltage safety which will cut out to protect the ECM but I don't know it's specs.
Bu the way the engine is Kohler CH26S EFI PS-78517

Thanks for your expertise

I think 12.7 volts is closer to normal battery voltage than 12.4V. If that battery has been receiving 14+ V for any length of time, it should be 12.7 V or very close.

cpurvis said:

I think 12.7 volts is closer to normal battery voltage than 12.4V. If that battery has been receiving 14+ V for any length of time, it should be 12.7 V or very close.

Click to expand...

Thanks for the reply. I checked the standing battery voltage prior to starting and the machine had sat for 24hrs. It still shows that the battery is losing charge over a short period of time.
Unfortunately I will not get back to repair the machine for at least a weak. I will make sure to get back to the forum with my results.