Charger shows E10 and does not respond to plug-in; LEDs may be frozen in one state.

Safety first: Disconnect power at the breaker before removing covers.

• Power cycle: Turn off the breaker for at least 5 minutes to fully discharge internal capacitors, then restore power. Observe whether E10 clears.
• Check low-voltage harness: Inside the unit, verify that ribbon cables or low-voltage harnesses between the display module and main control board are fully seated and undamaged.
• Inspect for surge damage: Look for burn marks, bulging capacitors, or a burnt smell on the control board. If present, the board must be replaced.
• Firmware update (if supported): Some Sun Country Highway models allow firmware reflash via service port. This should be performed only by authorized service personnel using official firmware.
• Replace control board: If connections are good and power cycling does not clear E10, replace the main control board assembly.