# electric clutch causes amp meter to go negative



## mkinsey7 (Jun 13, 2011)

I have a 25 hp kohler in a GT5000 craftsman, when I engage blades, electric clutch, my amp meter goes 5 amp negative, turn off and back to 0. every thing seems to be working fine. Any idea what might be causing this?


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## jhngardner367 (Apr 5, 2011)

Those clutches use a lot of amps.
5 amps negative is not bad.
My JD runs almost 10 negative.


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## Bill Kapaun (May 8, 2007)

If it's 0 when not engaged, it's not charging. You can't charge a battery with 0 Amps.


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## jhngardner367 (Apr 5, 2011)

Very true,Bill,and when you shut the pto off,it should show above "0",because of the drain,...which means it's charging.
I've never been one to trust the cheaper gauges,where it just has the wire looped in a clip,instead of 2 connections.


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## mkinsey7 (Jun 13, 2011)

must be not charging cause meter returns to 0, but the next time I went to start I almost had to jump battery. Never had this problem before. any good way to test charging system?


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## jhngardner367 (Apr 5, 2011)

Post the model # of the tractor,so I know which system is on it,as far as amps.
In the meantime, use a volt meter,between +,and - battery terminals, with the engine running at full throttle,and it should show a rise in volts,as it charges.
If not,you should have the battery tested at AutoZone,Napa,etc.,depending on how old it is.
If it's over 3 yrs old,I'd suspect the battery!


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## Bill Kapaun (May 8, 2007)

I'd do it a bit differently.
I'd hook up the meter not running.
You'll get battery voltage.
Start it and at high engine speed, you should see something in the range of 13-14 volts.

I'll assume this is a Kohler CV-730?
IF so, the stator can be checked.
Disconnect the plug to the Voltage regulater.
Set meter to AC Volts.
At high engine speed, you should have 28 VAC MINIMUM.


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## Bill Kapaun (May 8, 2007)

What happened to the EDIT Function?

I forgot to say to measure between the 2 leads from the stator on the VR plug. I think they are Yellow wires.


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## RC Wells (Dec 26, 2008)

Up on the side of the Kohler engine is a potted diode system that regulates the voltage from the flywheel based alternator. It is a simple system that gates the AC from the alternator and converts it to DC for battery charging and operation of the mower's electrical systems. Check that with a voltage meter to assure the engine is outputting DC voltage to the battery when the engine is running.

The diode has three pins, the two outside are the AC feeds from the alternator and the center is the DC feed to the battery.

Those diodes fail over time and you will likely see AC current on the two outside pins, meter set to AC and probes touching both the outside pins, and nothing from the center pin to engine block ground. If so, you need a new diode, and they are inexpensive.

If there is no power to the two outside pins, then the stator is due for replacement, and that is under the flywheel.


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## Bill Kapaun (May 8, 2007)

You describe a Voltage Regulator, (which the OP most likely has) NOT a diode.

A DIODE has 2 leads. In & out. It allows the positive half of the AC sine wave to pass and blocks the neg. half from flowing "backwards".

A Voltage Regulator has 2 AC inputs and and a DC out.
It converts both halves of the sine wave to + DC.

A DIODE is relatively inexpensive.
Voltage Regulators aren't.


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## RC Wells (Dec 26, 2008)

Bill,

You are sort of on track, but their is no regulator. The device is actually a bridge rectifier that does one purpose, it sinks the negative to the ground and the positive to the battery terminal. 

A rectifier is four or more diodes, and the device relies on the battery to function as a wet capacitor and sink the excess voltage as heat. Should you put an DC voltmeter on the DC terminal it will generate up to 56 volts at very low amperage when the engine is running full RPM without a battery (or a bad battery).

That is why mowers blow the lights and small switches if run with failing batteries. Too much voltage. 

I believe you will find most parts books for the component call it a diode.

Randy


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## Bill Kapaun (May 8, 2007)

I'm more then on the "right track!

How many Kohler powered GT 5000's can you come up with that DON'T have a Voltage Regulator?

A rectifier can be ONE diode! It is NOT regulated, but typically a 3 Amp circuit so that regulation isn't as important.

A BRIDGE Rectifier uses 4 Diodes.
A VR likely contains a Bridge Rectifier + other components for REGULATION.
Newer ones may even be different?


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## mkinsey7 (Jun 13, 2011)

Sorry I have not gotten back. We have experienced unusual flooding, worst ever for our area. Hope to get back to mower soon. Mower is a craftsman 917-276240 a CV 730 engine.


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## Bill Kapaun (May 8, 2007)

Which has a 15 Amp regulated system.


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## mkinsey7 (Jun 13, 2011)

SO, how am I to check this out ?


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## Bill Kapaun (May 8, 2007)

By reading post #7?


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## RC Wells (Dec 26, 2008)

https://www.equipatron.com/kohler-pa-cv730-0028.html

Take a look at the photos, go to the one with the oil filter at the left bottom, and go up to the rectifier. Three leads. The two outside are AC and up to 50 Volts, check with AC volt meter with the engine running. The center is 12 Volts DC, check it with the engine running.

A good battery will act as a wet capacitor to stabilize the voltage on the DC terminal, and it will be from 13.8 to 15 with the engine at full throttle. If voltage is lower 13.8 with the engine running the rectifier is bad. Remember, for DC check the positive terminal of the voltmeter to the center lead, and the negative terminal to the engine block.

If the DC voltage is higher than 15 at full throttle, the battery is likely sulfated and starting to fail.

You will need a good battery to test using this method.

The other way to test is with an ohm meter and use the manufacture's stated specifications for testing the rectifier from the repair manual.


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## jhngardner367 (Apr 5, 2011)

I've never known a Kholer engine to specify "up to 50 volts(ac)".
They NORMALLY say 28-38vac,at least in my manuals,and classes they did.
Also,a low DC reading,or no change in the reading,OR too high a reading(DCV),means a bad regulator.
Anything above 14.5vdc,can cook the battery.


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## Bill Kapaun (May 8, 2007)

"I've never known a Kholer engine to specify "up to 50 volts(ac)".
They NORMALLY say 28-38vac,at least in my manuals,and classes they did.
Also,a low DC reading,or no change in the reading,OR too high a reading(DCV),means a bad regulator.
Anything above 14.5vdc,can cook the battery."

DITTO!

I think there are some ONAN models that are in that area of "up to 50 volts(ac)", but THIS IS A KOHLER!

Sulfated Battery? It'd probably been tossed before it got that bad. Bedsides, it's a CHARGING PROBLEM, not a starting problem.

Wet capacitor? This is a LAWN TRACTOR Forum. Besides, it's NOT a battery problem! It Starts!

IF the OP just does post #6 and/or 7, they should be "on the road to recovery".
It gives us a good start if additional help is needed.

We don't need the confusing "shenanigans".


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## mkinsey7 (Jun 13, 2011)

Big thanks to all. Finally got to be able to work on mower. Checked heart (battery) first, no problem. So went to the rectifier, touched it and the center wire fell out without the clip. Took out clip soldered wire on new clip, slipped back in and everything is working perfect now. It is nice to have the ability to tap into so many minds that can help especially dealing with electrical things like a rectifier. The only thing I know that sounds like rectifier is rectum,
Again, BIG THANKS


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## Bill Kapaun (May 8, 2007)

Glad you found it.
FREE & SIMPLE is best.


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