Controller displays “Undervoltage” or “Low Voltage” and drops the load; lights dim or equipment resets when generator runs.

Safety first: Turn the generator OFF and open the main breaker. Disconnect battery negative before opening covers.

• Check load size: Verify that the total connected load does not exceed the generator’s rated kW. Temporarily reduce load by turning off nonessential circuits and retest.
• Inspect throttle/governor: On air‑cooled Kohler units, inspect the governor linkage and throttle plate for binding, rust, or debris. Ensure the governor spring is intact and properly attached.
• Air and fuel: Replace a clogged air filter and ensure gas supply pressure is within Kohler specs. Low fuel pressure can cause low RPM and low voltage.
• Check alternator connections: Tighten all output lug connections and inspect for discoloration or melted insulation that could indicate overheating or partial shorts.
• Test no‑load voltage: With a qualified person, start the generator with the main breaker open and measure voltage. If voltage is low even with no load and engine at correct RPM, suspect a faulty AVR or alternator winding.

If undervoltage persists after verifying load and basic engine operation, have a technician test the AVR and alternator windings with appropriate instruments.