Kohler Command CV730S charging issues

[scottygreer]

I have a 2004 Husqvarna GTH2548 with a Kohler Command cv730s (25hp) on it. I am stumped as to why the charging system isonly delivering 9.3 volts at full throttle. I tested the regulator rectifier on a similar mower and it works perfectly. I also tested the stator and it shows, according to the service manual, to be working properly.

On the similar mower that I tested the rectifier on, it shows the stator output between 40 to 42 volts of AC current. On my mower, the stator puts out 36 to 38 volts of AC current. The Kohler service manual says anything over 28 volts AC is correct. I am leaning toward a faulty stator, but the test indicates that the output is good. Any help would be greatly appreciated. This one has me stumped.

 

[ILENGINE]

make sure the regulator rectifier is properly grounded. Even make a jumper wire to go from one of the mounting bolts, to a good metal ground on the engine if you have to. If the regulator isn't grounded properly it won't work. Also make sure you are getting 12v at the battery wire where it connect to the regulator.

 

[scottygreer]

I have made sure multiple times that it has a good ground and everything is making good contact. But for some reason I am only getting 9.4 volts of DC output from the rectifier. I can put that same rectifier on a different mower and it produces about 14 volts DC. All the recommended tests for the stator shows good.

 

[Fish]

Exactly how are you testing the alt/stator?

 

[scottygreer]

I am checking with a digital multimeter. I am checking the AC voltage of the two white wires coming out of the stator. I'm also checking the resistance of the two white wires coming out of the stator. The AC voltage is riding around 37 volts. The ohm reading between the two white wires is .03 ohms.

 

[Fish]

Are you reading the output voltage with the wire unplugged from the rest of the tractor?

The output a.c. voltage seems too high, never came across that before..

 

[scottygreer]

Yes, I am reading the DC voltage directly from the middle male prong coming out of the rectifier, where the purple wire connects.

I thought the AC voltage was good enough. But the other Kohler mower I tested is producing 42 AC volts and with 14 DC volts coming out of the rectifier. That's how I know the rectifier is good. I am pulling the flywheel when I get home to check out the flywheel magnets and the stator.

 

[Fish]

I had one I worked on a few years ago, the guy had brought it in several times before, after buying several batteries and rectifier/regulators, When I did the initial tests, it was putting out 16 volts ac at the stator leads, so the first thing I did
was pull the flywheel. I had to look like it twice, because it looked like some kind of bizarre birthday cake. Every magnet
was off and stuck to the stator, and the even gaps in between was packed tightly with dead grass, so the mower had been run like this a long time. At the same time, the customer came in to check on his mower. Of course he was pissed that he had
brought the mower in several times, and several hundred dollars before. I apologized, he said "No, you just started here."
I am pissed at that a-hole over there!!!"

He was pointing at one of the other mechanics trying to hide behind a computer monitor.

I was just totally amazed that the system was cranking out any voltage at all. When they had popped on the new regulator
before, the output voltage was showing over 13, so they called it fixed. So he was mowing for a while until the battery finally ran down. But the action of the cast iron flywheel running close to those magnets stuck to the stator still cranked out some voltage....

 

[scottygreer]

Well, pulled the flywheel and everything looked good. The magnets all seemed good, no cracks and all were glued to the flywheel and none looked to have shifted. I swapped the stator and I am still getting about 38-40 AC volts from stator and about 9.4 DC volts from the rectifier. I even swapped the rectifiers and DC volts never changed. After starting the mower, I also unplugged the 6pin connector from engine to mower and disconnected the battery, both pos. and neg. leads. It seems no matter what I do, I cannot get it to produce more than 9.4 volts.

 

[ILENGINE]

With the wires connected to the regulator what voltage are you showing at the B+ terminal on the regulator. Can be tested without starting the engine. On some mowers may have to turn on the key, on some it will show voltage without the key on.