Step 5: Running the wire to the furnace
Find a place where you want to enable/disable switch and run the 14-2 cable to the fan.
Pull the cable in the connection box, about 4", remove the plastic sheathing and strip the end of the wires about 1/2". Secure the cable by tightening the clamp in the box.
Do the same for the fan wires. Twist together the stripped ends of common wire with the white wire and then turning clockwise twist the marrette on the ends.
Connect the black wire to yellow or red following the procedure above.
The bare wire and the ground wire go together and they are attached to the box. You can either connect them directly to the box or use a "pig tail" bare wire with one end connected to the box and the other to the bare wire coming from the furnace and the ground coming from the fan.
The black wire is always the live wire (by code). One way to remember which one is live is that death is black and if you are messing around with a live wire the black death is just around the corner.
If you ever need to use a different color wire just wrap a piece of black electrician's tape on it to indicate that the wire is the live one.
Pull the 14-2 in the switch box and prep it for hooking it up to the switch by removing the plastic sheathing and striping the ends.
Staple the cable once you're done with the connections.