As the title says my furnace blower fan will not turn off. Iíve watched some YouTube vids on diagnosing the problem and this is how far Iíve gotten. I have three control cables coming into the furnace. One 6 wire , one 4 wire and one 2 wire. The 6 wire goes to the thermostat. The 2 wire is connected to the cooling(y) terminal and the common terminal. Iím not sure about were the 4 wire goes. I can only guess it also goes to the air conditioner.the fan wire(green) of the thermostat is spliced onto the black from the 4 wire. And then the green from the 4 wire is terminated on the control board under the g terminal. The red from the four wire is terminated under the r terminal with the red from the thermostat wire.the white from the four wire is not in use. I turned the power off and checked continuity on my thermostat wires. They were good I found no shorts. Then I checked the four wire. There is continuity between the red and the green wire.that to me explains why the fan is continually on. I decided to disconnect the four wire completely. I unspliced my green thermostat wire from the black on the four wire and terminated it directly on the control board. I turned the furnace on and the fan did not turn on. Success! Or so I thought... when I turned up the thermostat the furnace kicked on and it got hot fairly fast. My fiancť was upstairs and said she could smell burning coming out of the heat vent. The furnace wasnít even on for 1 minutes before this happened. I turned the furnace back off immediately. I hooked everything back up the way it was and it works like it did before. The fan is still on continually. I know the fan is staying on because of the continuity between the red and the green in the 4 wire. What I donít know is why there is continuity. The only this I can think of is thereís a short somewhere. Iím running out of ideas. Is it normal for there to be continuity between these two wires? Any help would be greatly appreciated. I should also note that Iím a third year electrical apprentice. I have a multimeter to test for voltage and continuity.