L118 won't charge battery

[HarveyDog]

I have an L118 that hasn't charged right for years. I've been jumping it off my car each week.

Finally I spent some time and disconnected the alternator from the regulator. With the engine running full throttle, I get 30+ volts from the alternator. When I reconnected the (original) regulator, I got zero volts from it.

I bought a new regulator and I still get no volts from it.

Am I being stupid here? Do I just have a bad regulator? Or is it possible I'm getting 30+ volts out of the alternator and not enough amps?

It is possible to connect the regulator to 110v home current to test it? Or is this too high an input voltage for it to regulate?

Thanks, Harv

 

[RandyT]

Two things to check. Do you have 12V to the regulator from the battery. The other thing to check is to make sure the regulator is grounded. Kohler had some issues with regulator grounding a few years ago, because of paint on the regulator mounting screws.

 

[HarveyDog]

Thanks Randy.

12V to regulator from battery >> The flow is from regulator *to* battery, not vice versa. I unplugged the output (red) wire from the regulator and got fluctuating, (often zero), voltage. I guess this could be due to the ground issue.

Note also that the headlights are very dim, probably a symptom of the overall problem.

thanks, -Harv

 

[GManBart]

Thanks Randy.

12V to regulator from battery >> The flow is from regulator *to* battery, not vice versa. I unplugged the output (red) wire from the regulator and got fluctuating, (often zero), voltage. I guess this could be due to the ground issue.

If you ask ten electrical engineers which way the flow goes, half will agree with you, and the other half will say it's the other direction.

The difference of potential between the two points is what matters (definition of voltage), not really which way the current is flowing in this case. What voltage do you get between the alternator, and regulator?

Who makes the machine, and can you find the wiring schematic for it?

You likely can't use you home 120V power to test it because that's AC current, and external regulators (not part of the alternator) are normally DC. The alternator makes AC current, then rectifies it to DC before output.

 

[mitch becton]

first off do not hook 120v to this part you will have possibly smoke and fire. by some chance when you picked up regulator did they tell you it was also the rectifier maybe and by some chance does it have 5 to 7 plug ins. by deere pictures the charging sysytem works off the top of motor with a stator winding creating power these do go bad and some will have the ignition system wired into it making it a dual purpose part. do oyu have a alternator rebuilder in your town he can help with this if not sure post where you live i can get you in touch with a rebuilder who can check it for you. and by the way i am going out on a limb and say your reading of 30v is wrong even a full size alternator will not put out 30v it will catch on fire first good luck