Kohler CV23 Charging Issues

Well, I thought I had this battle won last year, but its reared its ugly head again. I mentioned last year I thought the battery was bad, and you all agreed, but let me recap the issue. Engine will run all day, as long as I dont engage the deck. When the deck is running, electric clutch btw, the battery will die after a couple of hours or so. At the time, I was getting 14.3 volts back to the battery when running. I replaced the battery, and all seemed well, as the mower always started after that. With the warm weather we had been having, I decided it was time to get the mowers ready. I charged the batteries, and installed, everything went fine. Decided Id knock down the wild onions, so I ran this mower for about 2 hours doing that. Yep, battery died.

So I pulled out my meter and started checking. I have 12.4 volts at the battery, and at each place I should have battery voltage. Had to jump it off, but I only had 12.2 - 12.3 volts while running, so that tells me charging system is faulty. (Both fuses were good btw.) At the regulator/rectifier, 3 terminals, at B I get the same reading of 12.3 - 12.4 volts running or not, at the other 2, what A1 and A2 or something, I get 49 - 50.1 volts while running with the connector OFF of the reg/rec, but connected no volts.

First question, even connected to the reg/rec, shouldnt I see the same voltage? Second, thats high for what Ive read. If its suppose to be between 28 - 32 volts, does it sound like the stator is putting out more than the reg/rec can handle and burned it out? What would or could cause this pike in voltage?

As usual, thanks!

One more thing I forgot. Everything Im seeing says I should have a ground wire on the reg/rec, but this engine has NEVER had one it. Even the manual for the engine that came with it has a pic of the engine with a ground wire on it. Would it hurt to out on to it, assuming it may be good?

"does it sound like the stator is putting out more than the reg/rec can handle and burned it out?"

I don't thin there's any way the stator can "put out too much voltage"

Voltage will obviously read higher open circuit and higher as engine speed is increased.

Need to check stator winding resistance and make sure it isn't shorted to ground, and check the rectifier/regulator.

Test info starts on about Page 45 in the factory manual linked below. Procedures are given for checking with Kohler special tester, and then with an volt ohmmeter.
Factory manual

If intended to be grounded it should be. Zener diodes, which are usually the regulating element in those devices, need to have a path to ground. If the diagrams supplied show the ground, do it. Jim

Ive done all of that. Signs point to a bad regulator. But if the info I have found is correct, I should only be getting 28 - 32 volts from the stator, Im getting 50. Like you, I dont see how it can put out more than it suppose to without a problem. BTW, the resistance was within spec, .0149.

I think maybe there was a revision to be book. The diagram shows it there, but there has never been a ground wire to it. The 2 screws went through the regulator, should and into the block, I think it was, or a bracket or something, I really dont recall, to ground it. Maybe my engine didnt have one originally, and I got a revised book. Think Ill run one and see what happens first

Your other issue is a mystery to me but I had a Scag walk behind with a CV20 Kohler that I bought new and when it was about 4 years old it quit charging and testing pointed to the regulator. A new one didn't fix it and for reasons I cant remember I tried grounding the regulator and it began charging. I them tried the OEM regulator with ground and it also charged. Why it quit working and then needed the ground remains a mystery.

If you are using a digital volt meter it might be giving you peak voltage indicated on the display. The RMS voltage might be closer. or use an analog meter. Jim

John,
Please post a pic of your regulator. I scraped out an 18 hp kohler engine, kept all spare parts. I may have one if I can remember where I put them.
geo

If your regulator is mounted into a plastic shroud it should have a ground wire attaching it to the block. The latest version of the Kohler manual for that engine states 28 volts AC minimum from the stator. Does not give maximum. I have seen voltage in the 45 range with no problems. Your local lawn mower shop should be able to test that regulator. You may need to check the amp draw of the electric clutch. It should not draw more than 6 amps.

Rodney 8)

Never had the ground wire on it. The shroud has only been off of it once. I do seem to recall the screws for the reg going into a metal bracket of something on the engine itself. I ran out of time today to try anything with it today.

Thanks for the offer George. I actually have another that I know ig good that I borrowed off of a mower that the engine is shot on. Boss said he was going to replace the engine anyways.

Make sure the regulator mounting area is clean, I have had some quit working because of crud build up around bolt holes.

Rodney 8)