Controller displays E7, generator runs but no AC voltage is present at the output lugs or transfer switch

Safety first: High voltage is present inside the generator when running. Turn the controller to OFF, open the generator main breaker, and disconnect the battery before removing any covers.

• Check generator main breaker: Verify the 2-pole or 3-pole main breaker on the generator is in the ON position. Reset if tripped.
• Inspect output lugs: With power off, remove the output terminal cover and check that all lugs are tight and free of corrosion or heat damage.
• Check wiring to transfer switch: Inspect the conduit and conductors between the generator and Champion automatic transfer switch (ATS) for visible damage.
• Visual alternator inspection: Look at the alternator windings and connections for burnt insulation or loose terminals.
• Test voltage regulator (AVR): If the engine runs normally but no or low voltage is present, the AVR may have failed. Replacement typically requires removing the alternator end cover and swapping the AVR module.

Because of shock and arc-flash hazards, internal alternator and AVR testing should be performed by a qualified technician with proper PPE.