not charging but 11 volts

J

jld54

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how do I check the voltage regulator on my Kohler 23.5 brand new engine
on my scag tiger cub
I had the old engine replaced because it blew up and now it doesn't want
to keep my battery charged
I can put my charger on it and it will last about a day before it won't crank
the engine
thanks
 
RDA.Lawns

RDA.Lawns

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You paid someone to put it on? If so take it back to them. Sounds like the rectifier is bad or they left a wire off. In the rush to finish the job.
 
reynoldston

reynoldston

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jld54 said:
how do I check the voltage regulator on my Kohler 23.5 brand new engine
on my scag tiger cub
Click to expand...

I don't know what you have for a Kohler engine so these are only guesses as to what you have for a engine and wire color. This is for a Kohler Command. You should have three wires going to the voltage regulator. The two outside white wires go to the stator under the flywheel. This test should be done at wide open throttle. You should be getting around 25 or more AC voltage at these two white wires and if not you have a stator problem. Now if that checks out OK check the center green wire in which you should be getting around 13.5 or more DC voltage. If not you have a bad voltage regulator. This is how you check your voltage regulator.
 
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bertsmobile1

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reynoldston said:
I don't know what you have for a Kohler engine so these are only guesses as to what you have for a engine and wire color. This is for a Kohler Command. You should have three wires going to the voltage regulator. The two outside white wires go to the stator under the flywheel. This test should be done at wide open throttle. You should be getting around 25 or more AC voltage at these two white wires and if not you have a stator problem. Now if that checks out OK check the center green wire in which you should be getting around 13.5 or more DC voltage. If not you have a bad voltage regulator. This is how you check your voltage regulator.
Click to expand...

A little bit out there.
Specs are 28V AC to 36V AC
25V AC can not yeild any more than 12.5V DC with no losses in the rectifier
28V AC will only give you 12V DC through the Std Kohler rectifier and you need 13 V min to charge the battery.
 
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ILENGINE

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And make sure the grounding strap or grounding wire is connected between the regulator and a good ground on the engine. The regulator won't work if it isn't grounded.
 
reynoldston

reynoldston

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bertsmobile1 said:
A little bit out there.
Specs are 28V AC to 36V AC
25V AC can not yeild any more than 12.5V DC with no losses in the rectifier
28V AC will only give you 12V DC through the Std Kohler rectifier and you need 13 V min to charge the battery.
Click to expand...

If you read my post it said OR MORE I put everything on the low side sorry about that.
 
reynoldston

reynoldston

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ILENGINE said:
And make sure the grounding strap or grounding wire is connected between the regulator and a good ground on the engine. The regulator won't work if it isn't grounded.
Click to expand...

Yes for sure seeing the engine has been changed. The voltage regulator sits in plastic on the Kohler command and needs a ground.
 
Last edited:
B

bertsmobile1

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reynoldston said:
Yes for sure seeing the engine has been changed. The voltage regulator sits in plastic on the Kohler command and needs a ground.
Click to expand...

And to make matters worse Kohler use a bent brass bus bar between the rectifier mounting bolts and a blower mounting bolt to provide this ground.
These regularly break at the bends and are hard to test so I toss them & fit a earth wire to both sides ( belts & Braces ) of the rectifier.

IF you are getting 13V or better at the middle terminal on the rectifier when at high idle ~ 3500 rpm but only show 11 V at the battery the ignition switch is usually the culprit.
On a couple of my customers mowers the previous service agents had bypassed the ignition switch and run the wire directly back to the battery.
 
I

ILENGINE

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bertsmobile1 said:
And to make matters worse Kohler use a bent brass bus bar between the rectifier mounting bolts and a blower mounting bolt to provide this ground.
These regularly break at the bends and are hard to test so I toss them & fit a earth wire to both sides ( belts & Braces ) of the rectifier.

IF you are getting 13V or better at the middle terminal on the rectifier when at high idle ~ 3500 rpm but only show 11 V at the battery the ignition switch is usually the culprit.
On a couple of my customers mowers the previous service agents had bypassed the ignition switch and run the wire directly back to the battery.
Click to expand...

It is Kohlers recommendation that if a mower comes into the shop and the charge wire goes through the key switch to clip the wire and mount it to the battery side of the solenoid. Kohler has had grounding issues with the regulators on and off for years. From the coating on the bolt that didn't provide a ground to the ground strap breaking to poor crimp connections on the grounding wire from the blowing housing bolt to the regulator bolt.
 
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