IMAGE COMING SOON
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
The B1370820 is a genuine Goodman blower-compartment door interlock switch, supplied complete with factory pre-wired leads for a plug-and-play install. It is a direct-fit replacement for the GMT045-3B and compatible Goodman/Amana furnaces. This safety switch cuts power to the furnace whenever the blower access panel is removed, preventing the unit from operating with the door open — a code-required protection against exposure to the blower and combustion area.
Choosing the genuine Goodman OEM assembly guarantees the correct actuator height, lead length, and connector so the door reliably trips the switch. Generic door switches often need splicing and may misalign with the panel, causing intermittent no-heat calls. The pre-wired OEM part removes that guesswork.
Easy–Moderate (2 of 5). Mount the bracket, route the leads, and connect to the existing harness. Disconnect power before servicing; consult a licensed HVAC technician if you are unsure.