Kohler cv15s not charging properly

[ILENGINE]

If you have 40 volts AC and 12.7 volts DC then that would indicate a bad regulator. They do make a tester to test the regulator but most people don't have one like I do where I work. Like ILENGINE said make sure that the ground wire/strap is present from one of the regulator mounting bolts and one of the blower housing bolts.

Easy way to check is to set your meter to DC volts and touch the red lead to the metal housing of the regulator, and the black lead to the engine block. See what the voltage is. Should be close to 0.

 

[relhok]

It sure looked like a bad regulator to me, too. After trying 3 different regulators though, maybe not. I have checked that the regulator is grounded, 0 volts from regulator case to engine block, also 0 ohms. Have also checked connections between battery posts and their respective clamps, and loosened, cleaned and reattached the battery - cable to engine block. I'll have another 'new' regulator this week, I'll post the results after it's installed.

 

[slomo]

98% of people overlook the grounds. Initial diagnostic testing always starts on the + side, for some reason??.

On mowers you need to check the engine mount to mower frame bolts are present and tight.

Some mowers will install the ground cable from the - batt post to the mower frame. Relying on rusty engine mounting bolts, paint and rusty frames to provide a poorer path back to the battery. They do this as it makes the ground cable shorter and long story short CHEAPER.

In reality, ground cable should go from batt - to the starter housing. Why? The starter is the highest amp draw device on a mower. Connected this way provides the best path for the starter to spin faster. Starter will perform better and last longer/run cooler with a better ground.

Looking at ground paths. A steel mower or car frame, with CLEAN bare metal connections carries current at a 70% value. A clean over amp rated/sized full copper wire is valued at 100%. So a clean steel frame connection starts out inferior. Then you add paint and rust...... Copper is better than steel as we all know.

You need to research star grounding washers, dielectric grease, hydraulic crimp tools and full copper lug connectors.

If you want a little more info, watch the below video. Look at WHAT they are trying to do and not HOW they do it. Most of these videos are wrong for this purpose. It's called the big 3 or big 4 upgrade.

 

[relhok]

Put the 2nd 'new' regulator on and got the same result. Battery voltage started at 13.2. Started the engine and voltage dropped to 12.5. Guess it's not a regulator problem. I'm looking at the grounding possibilities now. Thanks ILENGINE and slomo for your advice.

 

[Mattmotors]

My Kohler was not charging. All the magnets rusted off the fly wheel.

 

[relhok]

I finally found my problem. There are several sites that suggest unplugging the regulator/rectifier connector and checking stator output with engine running full speed. That's fine and well but you should then turn the engine off, reconnect the regulator connector, start the engine, run at full speed and check the stator output again. It should be around 30 vac or more. I did this and the stator output was 0 vac. This step is omitted on most forums. I also had failed to take notice of the stator resistance, which should be nearly 0 ohms, mine was much higher. I pulled the stator for inspection again. I saw a few specks of greenish corrosion, and looked at these with magnifying glass. Two of these areas had almost 'eaten' thru the copper winding. I removed these sections and rewound with good wire. May not be long lasting but it worked. After reassembly and with the regulator connector plugged in and engine at full speed, I had 30 vac from the stator and 14.5 vdc on B+. Hope this helps someone who has a charging problem.