Charger shows E20; unit may not energize even though all wiring appears correct.

Safety first: Ensure power is off before opening the enclosure.

• Check door interlock: Some Sun Country Highway models include a door or cover interlock switch. Verify that the cover is fully closed and that the switch actuator is properly engaged.
• Inspect switch and wiring: Confirm that the interlock switch is securely mounted and that its wiring harness is intact and firmly connected to the control board.
• Continuity test: A technician can test the switch with a multimeter to ensure it closes when the door is shut. Replace the switch if it fails.
• Safety relay: If the interlock hardware is good but E20 persists, the internal safety relay or its control circuit on the board may be defective and require board replacement.