* What model furnace do I have? BTUs 158; 1983; Series 100; Range 55-85 Motor -1/2 HP; Blower -197; Static Pressure- .5;Blades -3.5" Serial #3786010592 3-wire Pilot Safety Switch sx345nsx-12 wires runs to a connection for another set going to the blower fan. ***Should either set have been cut? If one were to be cut, which: attached to the box or to the blower? With the wires cut from the box, must I replace the safety switch as well?