Lennox 12M66 Wiring Harness 323080-701 Bypassing a safety device is

Bypassing a safety device is not recommended for permanent operation

the thermostat has failed and requires replacement

reducing amp draw under peak operating conditions

5kW kits and high-draw 5kW alternatives

Lennox 12M66 Wiring Harness 323080-701 Bypassing a safety device isThe Lennox 12M66 Wiring Harness (LB 99575) is a critical OEM electrical assembly engineered for precise signal routing and power distribution within residential and commercial HVAC systems. This genuine Lennox replacement part ensures seamless electrical communication between high voltage power supplies and low voltage control circuits, including connections for control boards, sensors, and motors. Designed to meet rigorous factory standards, the