Kohler Generator Error Code 08: How to Fix It

Medium 30-60 minutes High Severity Verified June 2026
Error Code
08
Brand
Kohler
Product Type
generator
Severity
High
DIY Difficulty
Medium
Estimated Fix Time
30-60 minutes
Error code 08 on a Kohler generator indicates under voltage, meaning the generator is producing voltage below the acceptable range. This can be caused by a faulty voltage regulator, a defective rectifier, or load issues. Follow these steps to diagnose and fix the problem safely.
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Tools You'll Need

How to Fix Error Code 08

  1. Safety First: Disconnect Load and Turn Off Generator

    Do not attempt any repairs while the generator is running. Risk of electric shock or injury.
  2. Check the Load

  3. Test Output Voltage with a Multimeter

    Be cautious of live terminals. Wear insulated gloves if available.
  4. Inspect the Voltage Regulator

    Disconnect the battery and generator control wiring before touching the regulator.
  5. Check the Rectifier Bridge

    The rectifier may be hot; let it cool down first.
  6. Inspect Wiring and Connections

    Ensure the generator is off before touching wires.
  7. Test the Generator Head (Optional)

    This test requires knowledge of electrical systems. If unsure, call a technician.

Parts You May Need

Voltage regulator (AVR)
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Rectifier bridge
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Voltage regulator (AVR)
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Rectifier bridge
Check Price on Amazon
Voltage regulator (AVR)
Check Price on Amazon
Rectifier bridge
Check Price on Amazon
Voltage regulator (AVR)
Check Price on Amazon
Rectifier bridge
Check Price on Amazon
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When to Call a Professional

If you have tested the voltage regulator, rectifier, and wiring and the problem persists, or if you are not comfortable working with high voltage, call a certified Kohler generator technician. Generator head repairs require specialized knowledge.

Frequently Asked Questions

What does error code 08 mean on a Kohler generator?
Error code 08 means the generator is producing voltage below the acceptable threshold, known as under voltage.
Can I reset error code 08 on my Kohler generator?
Yes, after fixing the underlying issue, turn off the generator, wait a few minutes, then restart it. The error code should clear.
Is it safe to run my generator with error code 08?
No, running with under voltage can damage sensitive electronics connected to the generator. Stop use until the issue is resolved.
What part usually fails causing error code 08 on a Kohler generator?
The most common cause is a faulty voltage regulator. The rectifier bridge is also a common suspect.
How do I test the voltage regulator on my Kohler generator?
Use a multimeter to check for correct output voltage. If no voltage or very low voltage is present despite proper engine speed, the regulator likely needs replacement.