Generator runs but controller displays E13 and may derate or shut down.

Safety first: Isolate the generator from the building and utility by opening the transfer switch. Turn OFF the generator and disconnect the battery before opening the alternator compartment.

• Confirm overvoltage: With the generator running no‑load in manual mode, measure output voltage with a true RMS meter. If voltage is significantly above rated (e.g., >130 V line‑to‑neutral on a 120 V system), shut down immediately.
• Inspect AVR wiring: Remove the alternator end cover and check the AVR connections. Ensure the sensing leads from the stator are firmly connected and not swapped or shorted.
• Check sensing leads to controller: Some WEN systems route voltage sensing to the main controller. Inspect these wires for damage or loose terminals.
• Adjust or replace AVR: If your AVR has an adjustment potentiometer, set it to the factory position and fine‑tune while monitoring voltage. If voltage cannot be brought into spec, replace the automatic voltage regulator (AVR).
• Controller calibration: If measured voltage is normal but the controller still reports E13, the controller's voltage sensing circuit may be miscalibrated or faulty. Replace the control board if necessary.