I have a forced-air gas furnace from the early 1970's. When I moved into my home, it had a dial thermostat. I replaced this with an electronic one and all works except the blower setting. I can adjust the heat from the thermostat, but I have to manually switch the blower on and off to get the heat pumping (walk down to the basement and flip the blower switch on the side of my furnace). When I installed the new thermostat, there was an extra wire that was not connected that I connected to the fan terminal(I just assumed this was the fan wire). It is a 3-wire deal. I would like the fan to automatically turn on and off(in coordination with the thermostat reaching a certain temp). This way I can have it turn on before I wake up and get home in the evening. Any idea if this is possible w/o looking at it?