KOHLER Confidant 7 generator

Discussion in 'General Electronics Chat' started by DwightAppleby, Aug 7, 2008.

  1. DwightAppleby

    Thread Starter New Member

    Aug 7, 2008
    5
    0
    1992 Kohler model 7CC KM21-RV Ser# 289391
    tech told me main circuit board is bad. and that it is a $1000.00 part plus installation charges. I live full time in my RV with my wife on a fixed income. so that is not an option. Does anybody know if it might be a reasonable assumption that if I remove the circuit board and bring it into an electronic repair they should be able to test the board and replace any bad transisters etc? I'm not very savy with electronics as you may have guessed.
    Please advise?
     
  2. DwightAppleby

    Thread Starter New Member

    Aug 7, 2008
    5
    0
    Oh yeah it's a 7000 watt generator. the symtoms are these:
    generator started cutting out and voltage fluctuated in and out just before it quit. The generator will start and continue to run as long as I keep the start button partially depressed. First the tech said it needed a Fuel regulator and $500.00 later he decided that was not the problem but that I needed a main control board he said the generator was only producing half the amperage it was designed to while running and so the control board signals the motor to shut down.
    is there anybody that can help me decide how we might best proceed?
    Thanks,
    Dwight & Ammiel
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Did the tech check to make sure that the brushes were free to move in their holders, and weren't overly worn?
     
  4. GeneratorPanels.com

    New Member

    Dec 5, 2008
    6
    0
    I know this is an old post, but I can't believe your were quoted $1K for the circuit board. Not sure if you fixed it yet, but...

    If the genset only runs as long as you hold the start button, the circuit board is most likely working as it should, and this failure mode indicates the circuit board is not receiving any AC output from the generator.

    The lack of AC output could be an easy fix (rotor and stator failures are not as common as the cheaper easier failures).

    For example, the brushes (not knowing the model and assuming this is a brush-type genset). The issue may not be the brushes themselves, but more commonly, the slip rings become "glazed" and prevent the brushes from being able to excite the rotor. They should be a bright copper color, but if they have a black glossy shine, a trimmed emory board is all you need to remove the glaze and restore the excitation. We have also seen cases where the wire brush leads get caught against the housing and prevent the brushes from reaching the rotor as they wear. Bottom line, no excitation through the brushes to the rotor = no AC output from the stator.

    The plug-in bridge rectifier on some models is another common failure that can mislead you. It is a small inexpensive part that is easy to replace.

    In some cases, either the voltage regulator or main control circuit board is the issue. An economical solution for the control board is repair rather than replacement. If this is the case and you choose the refurbishment route, generatorpanels.com can help you confirm the diagnosis and refurbish the circuit board (and provide a warranty).

    Good luck and happy holidays.
     
    Last edited: Dec 13, 2008
  5. DwightAppleby

    Thread Starter New Member

    Aug 7, 2008
    5
    0
    KOHLER Confidant 7 generator
    1992 Kohler model 7CC KM21-RV Ser# 289391
    tech told me main circuit board is bad. and that it is a $1000.00 part plus installation charges. I live full time in my RV with my wife on a fixed income. so that is not an option. Does anybody know if it might be a reasonable assumption that if I remove the circuit board and bring it into an electronic repair they should be able to test the board and replace any bad transisters etc? I'm not very savy with electronics as you may have guessed.
    Please advise?
    Problem has been ongoing for about a year now it's rough living in northern virginia in the summer without the generator working please help?

    Oh yeah it's a 7000 watt generator. the symtoms are these:
    generator started cutting out and voltage fluctuated in and out just before it quit. The generator will start and continue to run as long as I keep the start button partially depressed. First the tech said it needed a Fuel regulator and $500.00 later he decided that was not the problem but that I needed a main control board he said the generator was only producing half the amperage it was designed to while running and so the control board signals the motor to shut down.
    is there anybody that can help me decide how we might best proceed?
    Thanks,
    Dwight & Ammiel
     
  6. tincat2

    New Member

    Jun 7, 2007
    9
    0
    i don't know for sure what's going on here, but i do know i just saw a little used generac 7500w generator on craigslist for $400. i have that same generator and it does fine w/my place when i need it-one trip to your 'repair shop' would buy that. just a thought.
     
  7. DwightAppleby

    Thread Starter New Member

    Aug 7, 2008
    5
    0
    Thanks for taking the time to help us out.
    New development the generator will run as long as we have more than 1/2 a tank of fuel in the RV it has a safety shut-off feature that will not allow it to run if the RV has less than half a tank of gas.
    However the generator is still only putting out half the amperage it is designed to. It will run the lights but not the AC units.

    Please tell me; how do I check the brushes and do that deglazing thing you had mentioned Sir?
    I do have a multi meter on hand but I don't really know what to do with it...
     
    Last edited: May 12, 2009
  8. DwightAppleby

    Thread Starter New Member

    Aug 7, 2008
    5
    0
    Where can I find that again? Craigslist where? I'm in Northern VA Alexandria area...
    Thanks!
    D
     
  9. tincat2

    New Member

    Jun 7, 2007
    9
    0
    i thought it was pretty good too, since i paid 1200 for mine. the thing looked good in the pic. i don't remember the exact forum-i usually check the dc, annapolis, northern virginia, western maryland, and southern maryland forums for tools, general, materials, and electronics. this was in the last 4 or 5 days,but i doubt it's still there-lot of generators been out there lately, though. good luck!
     
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