Small Engines (Lawn Mowers, etc.)/Charging System


QUESTION: I Have A 25 HP Twin Just Replaced Voltage Regulator. When I Use The Electric PTO The Charge Light Is On, Turn PTO Off Light Goes Out. PTO Seems To Be Working Fine.

ANSWER: You really need to check the resistance of the PTO clutch.  Lots of information for Warner Electric Clutch resistance or Toro Electric Clutch testing.

Do you have a voltmeter to check for voltage and resistance?

Have you dis-connected the battery cables and cleaned the battery terminals and battery cable ends with a wirebrush...I have fixed a lot of charging problems just by cleaning the connections even though they looked clean.

Have you had the battery load tested to ensure the capacity is at the spec on the battery?

Any reason regulator may have failed?

What brand of mower do you have?

Recent friend kept burning regulators...turned out to be a bad key switch and melted electrical plug connected to the key switch.

Let me know.

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QUESTION: Mower Is A 2002 Troybilt Model 14AR809K063 Battery Is New 275 CCA. Terminals Clean And Tight. After Using Mower For Two Hours, Battery Still Charged. Started Mower, Battery Showed 11.9 V. Started Mower Deck, Battery Showed 11.77-11.78. Light Still On. Mower Deck Off, Turned On Lights. Discharge Light Glowed Bright, Wiggled Key Switch, Light Went Out. Tried That With The Mower Deck Running No Change. When Checking Out Put Of Alternator Do I Need To Put Both Probes On Each Pin From Connector.

ANSWER: What engine do you have?  Kohler or Briggs and Stratton?
What is the model, type and code or serial number.
Most newer models will have 2 wires coming from the stator...these are AC set the meter needs to bet set to AC and one meter lead on each stator wire...measure the AC output at full engine speed.

Let me know the engine information.

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QUESTION: Sorry. Engine Is A Briggs And Stratton Model 446777. Type 0106E1. Code 011205YG. It Is 25 HP. Thanks I'll Check Stator Output.

Use the URL below to identify your charging system:

This URL describes how to test the system:

Don't worry too much about the DC shunt.  They are very expensive, I have one, but rarely use it.  There are also plans on the internet for building your own.

Let me know if the URLs help.

Small Engines (Lawn Mowers, etc.)

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Eric A. Jones


Lawnmower Repair . Certified Master Service Technician from B&S. Have 23 years experience on B&S, Lawn Chief, Weed Eater, Echo, Peerless, Wheel Horse, Snapper, Atlas, MTD, McCulloch, Homelite and many other numerous brands. Specialize in electrical repair.


Born and raised in the midwest. Started tinkering with engines when I was about 14 on my Suzuki RM-80. I began lawn mower repair at a small hardware store. I knew absolutely nothing. I read lots of repair manuals and met an older fellow who taught me many lessons. I continued working on small engines through high school and paid my way through college working on mowers at the same hardware store. Decided to get away from the midwest and mower repair so I joined the Air Force. I repaired air traffic control electronic equipment and ended up in Hawaii where I got a part time job at Small Engine Clinic. I gained a lot of experience from the Small Engine Clinic and had a blast repairing small engines. I then took the Briggs and Stratton Master Service Technician test and earned my MST. I then traveled to Wisconsin where I attended the factory update training seminar and received formal training. Continued working on mowers part time as I completed 20 years of military. Retired from the military on a Friday and continued in the lawn and garden industry the next Monday.

MAS Aerospace Operations BA Mathematics AAS Electronic Communications AAS Electronic Technology

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