Thermostat Terminal Mapping Fix when Wires Swapped mid-install Learn how to fix swapped thermostat wires quickly and safely with a step by step guide for thermostat wiring, thermostat troubleshooting, and HVAC wiring repair. This short tutorial covers how to power down the system, read furnace and thermostat wiring diagrams, trace conductors, label wires, and verify continuity with a multimeter to prevent blown fuses and control board damage. Ideal for homeowners and DIYers facing incorrect ther