Kohler 26 hp Command charging problems

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goosemasterkl

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I have a Cub Cadet LT1050 w/26 hp Kohler Command engine and I'm having issues with the electrical system. The battery won't stay charged up when I mow. The battery is new. I took some measurements today with a digital voltmeter of the regulator/rectifier and the battery. Here are the numbers I got so maybe someone can lead me in the right direction on finding my problem.
1. Tested stator output at the rectifier plug- 47.8 volts ac
2. Tested rectifier/regulator @ dc volts output- 12.7 volts dc
3. Battery test with everything off including engine- 12.85 volts dc
4. Battery test with engine running at full speed- 12.6 volts dc
I can't pinpoint my problem; so any input from someone would be greatly appreciated. Thanks
 
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goosemasterkl

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I looked at the service manual and I don't have one of those Kohler rectifier testers; I took my readings using a digital voltmeter. I just put a new rectifier/regulator on the engine about a month ago. These problems seem to have started after the choke cable came in contact with the rectifier/regulator and welded itself across the terminals of the voltage regulator. Could that have caused the problems I'm having now? I put the old voltage regulator back on and both it and the new one tested the same on my readings I posted above. Confused and don't know which way to go. Could the choke cable incident have caused some other problems with say the stator or ignition modules? Thanks
 
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Rivets

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I don't use the Kohler tester, just a multimeter as you did. Your output DC voltage readings are too low. This would indicate a bad regulator/rectifier. If you have one that is mounted to the outside of the shroud, with three spade connectors, you may have a bad ground. Try adding a separate ground wire, which will run from the regulator body to a good engine ground. Also, check the output wire from the regulator all the way back to the battery, make sure it is not bad someplace. I've got a 10 hour day, so I don't know when I'll get to check the forum, but there are a couple other tech here that will be looking into this and hopefully they will have some help.
 
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ILENGINE

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Either a bad regulator or bad ground at the regulator. Take a multimeter and with the engine running put one lead on one of the mounting screws of the regulator, and the other lead on a good known ground. See what the voltage is. if the reading is much about a few tenths of a volt, you have a bad ground.

kohler has fought grounding issue at the regulator for years. Have went from a ground wire to a ground strap, to a special silver screw to attach to the ground strap, and back to the ground wire.
 
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goosemasterkl

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When I check with my voltmeter at the rectifier for ground problems; what does my meter need to be set on? Also; as I wrote ; this is a new voltage regulator and I was wondering what is blowing them, the original one and now the new one. Thanks
 
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ILENGINE

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When checking for ground issues the meter needs to be set on DC volts. If you have a ground problem the meter will show how much voltage is bypassing the grounding system of the component. If you are having repeat regulator failures I would be wondering if something is causing excessive amp draw. Faulty or shorted electric clutch. or something else in the system.
 
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goosemasterkl

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As I stated earlier about the choke cable came across the terminals of the voltage regulator/rectifier and welded itself to it. Ever since then these problems has occurred but I can't pinpoint what is failing. All I know is the battery keeps discharging as I mow the grass and it will get so low that the PTO clutch won't engage and I'll have to charge the battery back up to finish mowing. You can put a voltmeter on the battery and start it up then turn the blades on and you can watch the battery start to lose voltage on the meter. Maybe adding this extra info can give you a better way of pinpointing my problem. Thanks very much for your input.
 
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ILENGINE

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without the engine running what voltage are you showing at the B+ terminal on the regulator with the wires connected. Should show battery voltage. Depending on how the system is wired may have to turn on the key to get voltage. The other possibility could be the short that was caused by the choke cable may have melted some wires together in the wiring harness, causing a short which is overloading the regulator leading to failure.
 
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goosemasterkl

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I got 12.7 volts dc at the rectifier. Are you talking about the wiring harness at the rectifier maybe have shorted something out there? I know this has been a pain trying to get figured out. Like I stated earlier I really appreciate your responses. I had 47.8 volts ac coming out of the stator; does that voltage sound normal?
 
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